Cover page describe the Typical fracture surface of nuclear graphite blocks after irradiation (cracks occur during reactor operation). This picture Summarize the Fractographic studies of GR-280 nuclear graphite after irradiation up to neutron fluence above the turnaround dose (with a decrease in of the mechanical properties to the values close to the initial one after primary radiation-induced increase) showed along with the presence of transcrystalline fracture, appearance of intercrystalline fracture regions along the “filler-binder” type boundaries.
Joule heating of logs for phytosanitary purposes and timber processing pre-treatment
William J.B. Heffernan*, Nurzhan Nursultanov, Ryan van Herel, Thomas Smart
University of Canterbury Electric Power Engineering Centre, Christchurch, 8001, New Zealand
Adv. Mater. Lett., 2018, 9 (11), pp 767-775
Publication Date (Web): Jul 24, 2018
Copyright © 2018 VBRI Press
Joule heating has recently been investigated as a potential alternative to chemical fumigation for phytosanitary treatment of Pinus radiata logs exported from New Zealand. The research was driven by concern regarding the effects of methyl bromide release to atmosphere, following fumigation, as highlighted by the Montreal Protocol. The work has involved creating 1 dimensional and 3 dimensional computer models of the Joule heating process in P. radiata, building a laboratory-scale log test rig with suitable instrumentation and control systems, heating approximately 60 P. radiata logs and using the measured data to refine and validate the models. While engaged in this work it became clear that the process could also potentially be applied to heat veneer peeler logs. This paper describes the application of the 1 dimensional model and laboratory-scale test rig to a typical P. radiata export log and to a Eucalyptus nitens log prepared for veneer peeling. The results demonstrate that, despite the heterogeneities of the timber, the technique is capable of achieving the required temperature profiles for both applications and that the model is a sufficiently good representation of the process to provide a viable control method.
Ohmic heating, joule heating, phytosanitary treatment, peeler log heating, CFD modelling.