scholarly journals The research of some physical properties of wood Paulownia elongata and Paulownia fortuneii

2003 ◽  
pp. 211-221
Author(s):  
Borislav Soskic ◽  
Aleksandar Lovric ◽  
Boda Vukovojac

The density, shrinkage and swelling of Paulownia elongata and P. fortuneii wood were researched. The study material was provided by Boda Vukovojac, B. Sc., who established the Paulownia plantation and sample plots on the territory of the Municipality Bela Crkva. The study results show the differences between the analyzed properties of these two species. The study results were also compared with the results of the similar species of wood. The data shows that the study wood can be used in wood products that are not subject to great loads during exploitation. Further study should investigate the liability of these wood species to form tension wood and deformations in the conditions of variable hygroscopic moisture.

CERNE ◽  
2017 ◽  
Vol 23 (2) ◽  
pp. 153-160
Author(s):  
Stefania Lima Oliveira ◽  
Ticyane Pereira Freire ◽  
Tamires Galvão Tavares Pereira ◽  
Lourival Marin Mendes ◽  
Rafael Farinassi Mendes

ABSTRACT The objective of this study is to assess the effect of the laminar inclusion on the physical and mechanical properties of sugarcane bagasse particleboard. We used the commercial panels of sugarcane bagasse produced in China. To evaluate the effect of the laminar inclusion was tested two wood species (Pinus and Eucalyptus) and two pressures (10 and 15 kgf.cm-2) along with a control (without laminar inclusion). The panels with laminar inclusion obtained improvements in the physical properties, with a significant reduction in the WA2h, WA24h and TS2h. There was a significant increase in the properties MOE and MOR parallel and Janka hardness, while the properties MOE and MOR perpendicular decreased significantly. The pinus and eucalyptus veneers inclusion resulted in similar results when added to the panel with a 10 kgf.cm-2 pressure. The use of 15 kgf.cm-2 pressure is not indicated for the pinus veneer inclusion in sugar cane bagasse panels. There was no effect of the pressure level when evaluating the eucalyptus veneer inclusion on the properties of the sugarcane bagasse panels.


Author(s):  
Volodymyr Haskevych

The article presents the results of the study of Male Polissia podzolic chernozems profile degradation. The causes and consequences of this dangerous natural and man-made phenomenon resulting in changes in the habitus of soils, losses of soil mass and humus, deterioration of general physical properties and structural and aggregate composition, decrease in soil fertility and agriculture unprofitability on the slopes have been analysed. In the study of the profile degradation of podzolic chernozems, the following methods have been used: comparative-geographical, comparative-profile, soil-catena, analytical, and statistical. Field studies were conducted after the vegetation period. According to the study results, the thickness of the profile of weakly eroded podzolic chernozems, in comparison with non-eroded types, decreased by 17.0–35.5% as compared to the standard, which corresponds to satisfactory and pre-crisis condition, in medium eroded soils - by 32.2–63.4%, the degree of degradation is estimated as pre-crisis, crisis and catastrophic. In the highly eroded types, the thickness of the soil layer decreased by 47.8–74.9%, which indicates a high and very high (crisis) level of profile degradation. Erosion soil loss compared to the standard in weakly eroded podzolic chernozems is 1245.0-3744.6 t/ha, in medium eroded soil – 6762.4-8321.0 t/ha, and in highly-eroded soil – 8874.0-11595.0 t/ha. It has been established that chernozems as a result of water erosion from one hectare of weakly eroded podzolic, on average 39.47–118.70 tons of humus was eroded, 214.36-237.98 tons was eroded from medium eroded ones, and 240.49-267.84 tons from highly eroded soils. The average annual loss of humus is from 0.23-0.68 t/ha in weakly eroded types to 1.37-1.53 t/ha in highly eroded podzolic chernozems. Erosion processes result in deterioration of physical properties of soils. The use of dense and low-humus plumage horizons for plowing causes compaction of soils and deterioration of structure. Minimization of podzolic chernozem profile degradation in Male Polissia is possible provided that the system of anti-erosion measures, especially the conservation of highly eroded soils, the introduction of soil protection methods for soil cultivation, optimization of the structure of crop areas, ban on cultivated crops on slopes more than 3° steep, consolidation of small areas in larger arrays are applied. It is also necessary to introduce a system of basic and crisis monitoring over the condition of eroded soils. Key words: Male Polissia, podzolic chernozems, profile degradation, water erosion, humus, soil conservation.


Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1152 ◽  
Author(s):  
Christian Brischke ◽  
Lukas Emmerich ◽  
Dirk G.B. Nienaber ◽  
Susanne Bollmus

Sapling-wood products from different wood species such as willow (Salix spp. L.) and Common hazel (Corylus avellana L.) are frequently used for gardening and outdoor decoration purposes. Remaining bark is suggested to provide additional biological durability. Even for temporary outdoor use it seemed questionable that durability of juvenile sapwood can provide acceptably long service lives of horticultural products. Therefore, sapling-wood from seven European-grown wood species was submitted to laboratory and field durability tests. In field tests, specimens with and without bark were tested in comparison and submitted to differently severe exposure situations, i.e., in-ground contact, and above-ground situations with and without water trapping. All materials under test were classified ‘not durable’ independently from any potential protective effect of remaining bark, which contradicted their suitability for outdoor applications if multi-annual use is desired.


2008 ◽  
Vol 84 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Pierre Blanchet ◽  
Alain Cloutier ◽  
Bernard Riedl

Previous research has shown the possibility of making particleboards from bark residues. The objective of this study is to demonstrate the possibility of making black spruce (Picea mariana) bark particleboards with a short curing time in the pressing schedule, and to assess the effect of bark particle geometry on the mechanical and physical properties of bark particleboards. Additionally, melamine films were applied on bark composite boards and assessed. Mechanical and physical properties such as internal bond, modulus of elasticity, modulus of rupture, linear expansion and thickness swell were evaluated from five to two minutes curing time with a one-minute step. Mechanical and physical properties were also evaluated for four particle combinations. Different particles were used to qualify the effect of particle geometry. Combinations were made from two types of bark particles and two types of wood particles. These particles are hammermilled bark particles, refined bark, wood particles, and wood fibres (MDF). Melamine overlay was applied on the particleboard made with these four particle combinations to evaluate the behaviour of the film with the presence of bark in the composite. Good mechanical properties were obtained with a four-minute curing time. The use of wood fibres such as fibres from the MDF industry instead of wood particles, as in the particleboard industry, helped to reduce the linear expansion results. None of the particleboards produced in this study were able to meet ANSI standard requirements for linear expansion. The pressing of white melamine overlay results in a different colour according to the colorimeter results when it is applied on a bark particleboard compared to conventional particleboards. No differences were observed when a black film was applied. Key words: black spruce bark, bark particleboards, bark particle geometry, particleboard laminations, value-added wood products


2019 ◽  
Vol 11 (5) ◽  
pp. 1278 ◽  
Author(s):  
Cindy Chen ◽  
Francesca Pierobon ◽  
Indroneil Ganguly

The use of cross-laminated timber (CLT), as an environmentally sustainable building material, has generated significant interest among the wood products industry, architects and policy makers in Washington State. However, the environmental impacts of CLT panels can vary significantly depending on material logistics and wood species mix. This study developed a regionally specific cradle-to-gate life cycle assessment of CLT produced in western Washington. Specifically, this study focused on transportation logistics, mill location, and relevant wood species mixes to provide a comparative analysis for CLT produced in the region. For this study, five sawmills (potential lamstock suppliers) in western Washington were selected along with two hypothetical CLT mills. The results show that the location of lumber suppliers, in reference to the CLT manufacturing facilities, and the wood species mix are important factors in determining the total environmental impacts of the CLT production. Additionally, changing wood species used for lumber from a heavier species such as Douglas-fir (Pseudotsuga menziesii) to a lighter species such as Sitka spruce (Picea sitchensis) could generate significant reduction in the global warming potential (GWP) of CLT. Given the size and location of the CLT manufacturing facilities, the mills can achieve up to 14% reduction in the overall GWP of the CLT panels by sourcing the lumber locally and using lighter wood species.


2017 ◽  
Vol 97 ◽  
pp. 260-267 ◽  
Author(s):  
Steven F. Vaughn ◽  
James A. Kenar ◽  
Brent Tisserat ◽  
Michael A. Jackson ◽  
Nirmal Joshee ◽  
...  

2010 ◽  
Vol 5 (3-4) ◽  
pp. 151-161 ◽  
Author(s):  
Alexandre Charifo Ali ◽  
Jelena Chirkova ◽  
Nasko Terziev ◽  
Torbjörn Elowson

PERENNIAL ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Ifa Zanty Wahyuni ◽  
Musrizal Muin ◽  
. Suhasman

The effect of preservative treatment using carbon dioxide as a carrier solvent on wood physical properties and dimensional stability had been observed on three commercial wood species (Agathis sp., Palaquium sp., and Heritiera sp.). For the purpose of the study, wood samples measuring 1,5 (R) x 1,5 (T) x 15 (L) cm were prepared. Treatment was conducted at elevated temperature (50C - 350C) and increased pressure (60 - 80 kgf/cm2) on one occasion with five replicates using two specimens of each wood species for each treatment. The final treatment condition was maintained for three different periods (10, 20, 30 minutes). Results indicated that the physical properties and dimensional stability of the preserved wood were not significantly affected by the application of CO2 impregnation as carrier solvent. Key words: Preservative treatment, Carbon dioxide, Carrier solvent, Wood physical properties, Wood dimensional stability


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1519
Author(s):  
Jože Kropivšek ◽  
Matej Jošt ◽  
Petra Grošelj ◽  
Manja Kitek Kuzman ◽  
Mirko Kariž ◽  
...  

Invasive tree species continue to spread, so in addition to strategies to limit this their use in the production of innovative products must be considered. This research aimed to develop and apply a model for calculating the cost price of invasive wood products considering the specificities of materials and production process, and is suitable for quickly assessing the economic feasibility of using the selected tree species for a given product. The TDABC method with the inclusion of fuzzy logic was used to incorporate the uncertainty of time and quality parameters. In the model, the imprecise values of these parameters are represented with triangular fuzzy numbers. Using a furniture product (dining table) made of black locust wood as an example, we demonstrated the applicability of the developed model. We found that the most probable cost price of a table made of black locust wood is comparable to the price of a product made of oak wood. In this way, we proved the potentially high economic value of invasive wood. The innovative products from invasive non-native wood species can achieve a high added value due to their visual characteristics and attractive appearance. Such use could increase interest in the (more efficient) management of invasive tree species, which would help to manage and use them efficiently. For further research, it would be useful to apply the proposed model to other invasive tree species as well as to other products.


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