Journal articles

Benoit Belleville, Adam Redman, Phouluang Chounlamounty, Vansy Phengthajam, Si Xiong, Latsamy Boupha, Barbara Ozarska

 

Abstract

In Laos and neighboring countries, opportunities exist for the production of engineered wood products such as plywood and laminated veneer lumber to supply the rapid growth of construction, furnishing, and joinery activities. The objective of the present study was to assess the potential of peeling fast-growing high-yielding pulpwood from managed eucalypt stands in Laos for veneered products. Eucalyptus pellita, Eucalyptus camaldulensis, and eucalypt clone K7 (E. camaldulensis × E. deglupta) stands were characterized based on veneer quality and recovery. The influence of log position, log geometry, and other log traits during recovery were also investigated. The selected taxa achieved green veneer recoveries that ranged between 57% and 67%. End splitting and branch-related defects were the most important grade-limiting defects that restricted veneer sheet quality to a lower grade of most sheets. However, simple timely silvicultural decisions, such as pruning, could significantly help improve the quality of veneer obtained. The obtained results could be used in the formulation of recommendations to adopt better management practices in Laos to improve the value of plantation-grown wood.

Keywords

Rotary veneer; Eucalyptus pellita; Eucalyptus camaldulensis; Eucalyptus deglupta; Recovery; Grade quality
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Teak plantation smallholders in Lao PDR – Paper

The Evolution of Certified Teak Grower Groups in Luang Prabang, Lao PDR: An Action Research Approach

 

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Comparing two internal check measurement methods for wood drying quality assessment

Khamtan Phonetip, Barbara Ozarska, Graham Ian Brodie

Abstract

Internal checks that are created in the interior of lumber during or after timber drying seriously affect the quality and value of timber used for the production of high value wood products. This study compared two different methods of assessing wood drying quality, by using either an image analysis ImageJ or Digital Calliper technique, to determine the percentage loss of cross section due to internal checking. The study revealed that there was a significant difference in the total area of internal checks, but the overall timber quality classes determined from both techniques were identical based on the Australian and New Zealand standard for timber quality assessment.

Full paper please visit link https://www.tandfonline.com/doi/abs/10.1080/07373937.2018.1445638

 

Comparing two intermittent drying schedules for timber drying quality

Khamtan Phonetip, Barbara Ozarska, Benoit Belleville & Graham Ian Brodie

Abstract

Intermittent drying techniques for drying timber may provide various benefits by improving timber quality and addressing energy efficiency through saving in energy consumption. The purpose of this study was to compare two intermittent drying schedules applied in the treatment of Eucalyptus delegatensis boards, through assessing surface and internal check development, moisture content (MC) profiles during drying, and timber distortions at the end of drying. The study used identical conditions during the heating phase at 45°C/60% relative humidity (RH), except for RH during the nonheating phase (80 and 90%). The results, discussed in this paper, analyzed the timber quality during and at the end of drying. The different RH during the nonheating phase did not generate a significant difference in MC at the case boards between the two drying schedules. The assessed quality of timber at the end of drying was based on AS/NZS 4787:2001. MC gradient, drying stress residual, internal checking and collapse were graded as class “A” (class A is the highest grade and D is the lowest). Bow, cupping, and spring were under the permissible levels based on grading standard AS 2082–2007. Measured data were validated using Drytek® simulation software showing MC movement in case boards.

Full paper please visit link https://www.tandfonline.com/doi/abs/10.1080/07373937.2018.1445638

 

Drying timber in a solar kiln using an intermittent drying schedule of conventional laboratory kiln

Khamtan Phonetip ,Graham Ian Brodie ,Barbara Ozarska &Benoit Belleville

Abstract

The purpose of this study was to apply an intermittent drying schedule developed from a conventional kiln to a solar kiln. Implementing this experiment could help better understand the oscillation of the temperature inside a solar kiln and timber quality during drying progress. The theoretical recharge and discharge curves were used to predict the temperature inside the solar kiln using experimental data obtained previously using a solar kiln. The surface and internal checks were measured using ImageJ freeware, and the development of the Moisture Content (MC) profile was assessed by coring and slicing method for the Eucalyptus delegatensis boards during drying. The results showed that the recharge and discharge model can predict the temperature with less than 2 °C error from the experimental data in the solar kiln. The total drying time to 12% MC was 87 days for the solar kiln. The drying rate was equivalent to the conventional kiln decreasing at an average rate of 0.2% per day. The surface check formation was found when the MC gradient between the core and the case of the board was greater than 42% at 9 days of drying in the solar kiln and conventional laboratory kiln. The applied drying schedule used in the solar kiln was successful and offered similar drying time. However, the oscillation of temperature in the intermittent drying will require further improvement to get closer conditions in a solar kiln.

Full paper please visit link https://www.tandfonline.com/eprint/8iSaKPQGVthRBwhyyeaI/full

 

Simulating Solar Kiln Conditions using a Conventional Kiln

 Khamtan Phonetip, Graham Ian Brodie, Barbara Ozarska, Benoit Belleville

Abstract

This study assessed the possibility of using a conventional laboratory kiln to simulate solar kiln conditions and developed a mathematical model to predict the timber quality and moisture content profile during drying. The simulated temperature in the kiln was modelled on the actual temperature of a solar kiln based on the climatic conditions of Vientiane, Laos. The modelling for moisture content profile in boards was implemented in Matlab codes, which combined fundamental equations and validated the model with measured data. Timber quality assessment was performed based on quality standard AS/NZS 4787 (2001). The simulation results were similar with the measured solar kiln temperatures to within less than 2 °C in a day. The modelling correctly described the MC profile decrease during the drying process when compared with measured data. Further work is required regarding the method of measuring the MC data and anatomical properties. Assessed against the standard, timber quality at the end of drying was all graded as Class “A”, and timber distortion was within permissible limits.

Full paper please visit link

http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_13_2_3740_Phonetip_Simulating_Solar_Kiln_Conditions_Kiln

 

Applying a GIS-based Fuzzy Method to Identify Suitable Locations for Solar Kilns

Khamtan Phonetip, Barbara Ozarska, Graham Ian Brodie, Benoit Belleville, Latsamy Boupha

Abstract

The aim of this study was to identify suitable locations for solar kilns in Vientiane, the capital of Laos, based on geographical and climatic conditions and restricted areas. The criteria of the parameters, which were incorporated with Fuzzy membership functions, were used to create layers in the ArcGIS environment to draw maps of suitability. Climatic parameters, based on the Fuzzy method, were used to investigate the period of productive performance for solar kilns. The results showed a range of possible locations. The most suitable locations were in flat areas near roads. They were far from protected areas, rivers, and flood prone areas. The most productive performance period for operating solar kilns was from November until May.

Full paper please visit link http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/Biores_13_2_2785_Phonetip_GIS_Fuzzy_Method_Solar_Kilns