Applied Tropical Agriculture

 Journal

 Assessment Of The Differences In Drying Rates Of Open Air And Shed Methods Using Three Selected Nigerian Wood Species

 Aladejana J.T., Owoyemi J.M. And Olufemi B.

 2014

Differences in drying rated of open air and shed methods using three selected Nigerian wood species was examined. The samples of the three wood species; (Brachystegia eurycoma, Trichilia emetica and Cordia millenii) were collected form freshly sawn logs form a sawmill in Akure Nigeria for evaluation. They were processed into 300mm (length) x 100 mm (breadth) x 100 mm (thickness) blocks weight and stacked in each of the drying medium for rate of drying assessment. The results of the study indicated that Brachystegia eurycoma dried form 41% and 40.5% to 24.4% and 20.8%, Trichilia emetic dried from 38.5% and 36.5% to 19.1%s and 18.3% while Cordia milenii dried form 38% and 37.9% to 17% and 16% respectively for open air and shed methods after 21 days of drying. The density of the wood species as obtained from literature influenced the drying rate. There was significant difference (p 

 Nigerian Journal Of Forestry

 Journal

 Dimensional Stability Of Paper Cement Bonded Ceiling Board Made From Recycled Paper

 Owoyemi J.M. And Ogunrinde O.S.

 2013

The effect of mixing ratio and paper blending proportion on paper cement bonded ceiling boards’ dimensional stability was investigated using water absorption and thickness swelling tests at 24, 48 and 72 hours of soaking. These boards were made from 100% old Newsprint paper, blend of Newsprint and Kraft paper at 50:50 and 100% Kraft paper mixed at cement/ paper ratios of 1:1, 2:1 and 3:1 and CaCl2 additive concentration of 3%. The variation in the blending proportion and mixing ratio affected the density and dimensional stability of the boards. Boards of higher mixing ratio and density absorbed less water than those of low mixing ratio because higher cement content and resultant higher density determined the moisture intake of the boards. The results showed that there was difference in water absorption at the different hours but there were no changes in thickness swelling after 48 and 2 hours soaking. The highest level of water absorption and thickness swelling were recorded at the lowest mixing ratio of 1:1 and 100% blending of Newsprint alone. It was observed that water absorption and thickness swelling reduced with increase in mixing ratio and blending proportion. The results further revealed that boards made from 100% Kraft paper were dimensionally stable and addition of Kraft paper to Newsprint at 50:50 ratio improved dimensional stability. This made the boards durable and suitable for use where ceiling board is prone to shrinkage and in an environment of high humidity which cause swelling panel products. 

 ProLigno International Journal In The Field Of Wood Engineering

 Journal

 Effect Of Density On The Natural Resistance Of Ten Selected Nigerian Wood Species Subterranean Termites’ Attack

 Owoyemi, J.M., Olaniran, O.S., And Aliyu D.

 2013

The effect of density on the natural resistance of selected Nigerian wood species to subterranean termites was investigated. Wood samples obtained from mixedconversion boards were used such that the samples contained both sapwood and the heartwood. They were sawn to 35x35x450mm stake and dried at 103±2°C till a constant weight was achieved. Density of the selected wood species was determined. Based on the observed average density, the wood species were classified into high, medium or low density. Graveyard test method was used to assess the natural resistance of the samples on a site dominated by Macrotermes sybhylinus, a family of subterranean termites. Weekly visual observations of the stake were taken as specified in ASTM D334580 Standards for 24 weeks. The wood samples were withdrawn at the 24th weeks of exposure to termites and weight loss due to termites’ attack was estimated. Result obtained showed the relationship between wood density, weight loss and the ASTM ratings. A strong but negative correlation (R2 = 0.70) existed between weight loss and wood density while as strong positive correlation (R2 = 0.83) existed between ASTM values and wood density. These results indicated that wood species in the high density class had a better resistance to termite’s attack. The influence of mixed conversion on the resistance of wood species to subterranean termites was also reported, since it is the most common method of conversion in the Nigerian sawmills. The sapwood of high density species are not durable as revealed in the study thus the preservative treatment is imperative for long service life. 

 Journal Of Sustainable Environmental Management

 Journal

 Chain Sawmilling: Implications On Nigerian Forest

 Owoyemi J.M., Falemara B.C. And Omolola O.R.

 2013

Chainsaw is a major mechanical harvesting tool used in tree felling and adapted for log conversion which involves insitu cutting of logs into timber. The trees are felled, topped, delimbed, cross cut and then processed into timber. In recent times, its use has gone beyond the traditional felling and now commonly used for log conversion in the forest. This development has generated a lot of controversies in some states in Nigeria. While some states outrightly banned its use, others condone it. This paper examines the practice of chainsaw milling and its implications for the future of Nigerian forests. Root causes of illegal chainsaw milling activities as well as environmental concerns were also discussed. Illegal chainsaw lumbering is reported to be destructive to the forest resource base and yield low timber volume recovery. While this practice provides affordable cheap timber supply and also generate employment for rural people. The practice of chainsaw milling should be regulated and operators made to conform to the provisions of the law to stem the spate of indiscriminate exploitation of the forest and loss of revenue for the government. 

 Nigerian Journal Of Environmental Management

 Journal

 Physical Properties Of Selected Indigenous Wood Species In Akure, Ondo State, Nigeria

 Falemara, B.C. Owoyemi, J.M. And Olufemi, B.

 2012

The identification of wood is of prime importance to primary and secondary industrial users of wood as well as to scientists in the field of botany, ecology, forestry, and wood technology. Since wood is a popular and useful material, it is important that professionals be able to distinguish the wood of one species from another. Wood can be identified by using features like mechanical strength, density, hardness, odour texture and colour. Reliable wood identification usually requires the ability to recognize basic differences in cellular structure and wood anatomy. This study was carried out to determine some physical properties of ten selected indigenous Nigerian wood species namely: Abura (Mitragyna ciliata), Afara (Terminalia superba), Araba (Ceiba pantandra), Aye (Sterculia rhinopetala), Idigbo (Terminalia ivorensis), and Iroko (Milicia excelsa). Others include Obeche (Triplochiton scleroxylon), Ofun (Mansonia altissima), Omo (Cordia milleni) and Opepe (Nauclea diderrichii). The physical properties of wood species that were studied include; the grain pattern, texture, colour, vessels (pore) distribution and arrangement, rays, density and specific gravity of the wood species. The wood species were collected from different sawmills in Akure, whose major source was Akure forest reserve and its environment. Observations were carried out and the results obtained were compared with information from past records and research made previously on the selected wood species. The result of the study showed variation in all the properties studied. This result and information obtained on the physical properties of the selected wood species were documented and this could be used as baseline information on identification of the wood species, research work and future referencing. 

 ProLigno International Journal In The Field Of Wood Engineering

 Journal

 Evaluation Of The Resistance Of Gmelina Arborea Wood Treated With Creosote Oil And Liquid Cashew Nut Shell To Subterranean Termites’ Attack

 Owoyemi J.M., Kayode, J.O. And Olaniran S.O.

 2011

This study examined the resistance of Creosote Oil (CREO) and Cashew nut shell liquid (CNSL) on the protection of Gmelina arborea wood against subterranean termites’ attack. Gmelina wooden stakes were treated with undiluted CREO and with diluted CREO/ kerosene mixtures ratio 1:1 and 1:3, using cold dipping method. Termites’ field exposure test was carried out at the timber grave yard for 36 months (3years) to test the resistance of CREO and CNSL preservatives to subterranean termites. Weekly visual observations according to American Standards for Testing Materials (ASTM) were taken to find out the effect of prolonged exposure of treated wood samples had 54.2, 65.0 and 76.0% weight loss compared to the control (untreated) sample having 86.7% respectively for the same period. CNSL treated samples had 80.0, 80.8 and 85.0% weight loss respectively compared with the control with 86.7%. These results indicated that CREO treated samples provided a better protection against subterranean termites compared with CNSL treated samples for the 36month period. 

 Forest And Forest Products Journal

 Journal

 Effects Of Age On The Natural Resistance Of Gmelina Arborea (Roxb) Wood To Subterranean Termites’ Attack

 Owoyemi J.M., Kayode J.O. And Olaniran O.S.

 2011

This study examined the natural resistance of Gmelina arborea wood to termites’ attack. Untreated Gmelina arborea wood of ages 10, 15, 20 and 25 years respectively were exposed to termites at the timber graveyard. Visual examination according to American Society for Testing Materials was carried out for a period of 18 months. The result showed that Gmelina arborea wood attained a visual rating of 3.5 and 2.8 for ages 25 and 20 years in the 18th month, 15year old wood attained a visual rating of 0 at the 18th month while the 10year old wood attained a rating of 0 at the 12th month. This result showed that the visual rating for the ages examined were tending towards zero or completely failed before the 18th month. The result indicated that Gmelina arborea wood is not naturally resistant to termites. However, the study revealed the effect of age (maturity) on the ability of the wood to withstand attack. It is therefore necessary that Gmelina arborea wood be treated with preservative irrespective of the age at which it is procured to extend its service life beyond the level of its natural durability. 

 Nigerian Journal Of Mycology

 Journal

 Fungicidal Effect Of Chromated Copper Arsenate And Cashew Nut Shell Liquid On The Treatment Of Ceiba Pentandra Wood

 Owoyemi J.M., Olufemi B. And Olaniyan M.O.

 2011

The fungicidal effect of Chromated Copper Arsenate (CCA) and Cashew Nut Shell Extract (CNSE) on the treatment of Ceiba pentrandra wood against fungal infection was investigated. Ceiba pentrandra wood samples of size 20 x 20 x 60mm were treated with CCA and CNSE preservative using cold dipping method. Absorption and retention of the preservatives using CCA at 4% concentration gave 65.75% and 10.23 kg/m3 respectively while undiluted CNSE recorded 31.4% and 0.79 kg/m3for the aforementioned respective parameters. The result of fungal exposure test for 12 weeks by soil block method revealed the efficacy of CCA in suppressing the activities of Serpula lacryman, Aspergulus wentii and Penicilium brevi – compatum on C. pentandra wood while CNSE could not provide the needed protection as there was no significant difference between CNSE treated samples and the control. 

 Forest And Forest Products Journal

 Journal

 Influence Of Preservative Viscosity On Absorption By Gmelina Arborea Wood

 Owoyemi, J.M.

 2010

The effect of preservative viscosity on fluid absorption by Gmelina arborea wood was investigated using Copper Chrome Arsenate (CCA), Creosote Oil and Cashew Nut Shell Liquid (CNSL) preservatives. Viscosity test was carried out on these preservatives using viscometer. Hot and cold dipping methods of applications were used for the preservative treatments on Gmelina arborea wood. The result revealed that hot treatment method lowered preservative viscosity and improved its uptake by the wood with percentage absorption of 9.65± 4.32 compared with cold treatments. Also, there was significant difference between CCA and the other two preservatives in the absorption capacity of Gmelina arborea wood. The highest percentage absoption of 13.94 ± 3.7 was recorded for CCA, followed by CREO with 9.84 ± 4.32, while CNSL has the least absorption of 5.18± 1.3 for hot treatment. The result of viscosity test for the preservaties when compared with absorption showed that absorption is greatly influenced by the rate of preservative applicatipon. 

 Journal Of Bio Technology

 Journal

 Effect Of Incision On Preservative Absorption Capacity Of Gmelina Arborea Wood

 Owoyemi, J.M. And Kayode, J.O.

 2008

The effect of incision on preservative absorption of Gmelina arborea wood was investigated using Copper Chrome Arsenate (CCA), Creosote Oil and Cashew Nut Shell Liquid (CNSL) preservatives. The result revealed that incising improved the uptake of the preservatives by the wood with a percentage absorption of 9.44±2.96 compared with unincised; 7.83±2.96. Using 555 incisions m2 to an incision depth of 5mm statistically showed significant difference between incised and unincised treatments. Also, there was significant difference between CCA and the other two preservatives in the absorption capacity of Gmelina arborea wood. The highest percentage absorption 13.60±1.91 was recorded for CCA, followed by Creosote Oil 7.8±0.66, while CNSL has the least absorption 6.92±0.08.