ProLigno International Journal In The Field Of Wood Engineering
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.
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withdrawn at the 24th weeks of exposure to termites and weight loss due to termites’ attack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.
International Journal Of Chemical, Material Science And Engineering
Suitability Of Newsprint And Kraft Paper As Materials For Cement Bonded Ceiling Board
Owoyemi J.M. And Ogunrinde O.S.
The suitability of Newsprint and Kraft papers for the production of cement bonded ceiling
board was investigated. Sample boards were produced form newsprint paper (100%), mixture
of newsprint and Kraft paper (50:50) and Kraft paper (100%) at 1:1, 2:1 and 3:1 cement/
paper mixing ratio respectively with 3% additive concentration of calcium chloride (CaCl2).
Density, flexural and thickness swelling properties of the boards were investigated. The
effects of paper type and mixing ratio on the physical and mechanical properties were also
examines. The bending properties of the board which include Modulus of Elasticity (MOE)
and Modulus of Rupture (MOR) increased linearly with increase in density. Modulus of
Rupture of boards increased as the density and mixing ratio increased. The thickness swelling
property for the two paper types decreased as the board density and mixing ratio increased.
Boards made from Kraft paper recorded higher strength values than the ones made from
recycled newsprint paper while the mixture of Kraft and newsprint papers had the best
surface finish. The result of the study will help in managing the large quantity of waste from
paper converting/ carton industry and that the ceiling boards produced could be installed with
clout nails or used with suspended ceiling fittings.
Journal Of Sustainable Environmental Management
Chain Sawmilling: Implications On Nigerian Forest
Owoyemi J.M., Falemara B.C. And Omolola O.R.
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,
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
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.
International Journal Of Biological Sciences And Applications
Natural Resistance Of Ten Selected Nigerian Wood Species To Subterranean Termites’ Attack
Owoyemi J.M. And Olaniran O.S.
Natural resistance of some wood species used prominently in the Nigerian construction
industries to termite was examined in this study. Wood samples were collected from a
Sawmill in Akure and cut to stakes of 35x35x450 mm which were to be buried half way in
the soil. Their density was determined and classified across the three density classes: high,
medium and low. They were exposed to subterranean termites attack for 48 weeks
(12months) in a termitarium. Monthly visual estimation of the stakes was done in accordance
with ASTM D 3345/t980 rating scale and gravimetric weight loss assessment carried out after
6 and 12 months of exposure. Results showed that there was significant difference (p
Applied Tropical Agriculture
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.
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
ProLingo International Journal In The Field Of Wood Engineering
Strength And Sorption Properties Of Bamboo (Bambusa Vulgaris) WoodPlastic Composites
Babajide C.F., Ajayi B. And Owoyemi J.M.
The study investigated the strength and water sorption properties of plastic composites
produced from the sawdust of bamboo and recycled Low Density Polyethylene (LDPE).
Three levels of board density (500kg/m3, 600kg/m3 and 700kg/m3) and three levels of
plastic/ fibre mixing ratio (1:1, 2:1 and 3:1) were adopted. The thickness swelling (TS), water
absorption (WA), tensile strength, modulus of elasticity (MOE) and modulus of rupture
(MOR) were investigated. The sorption properties were measured after 24hour watersoak
test exposure. The mean values of the properties ranged from 4.15% to 1.40% for thickness
swelling; 31.96% to 4/83% for water absorption; and 2.55Mpa to 6.98Mpa, 5564.11Mpa to
10771.65Mpa and 0.60Mpa to 4.2Mpa for tensile strength, modulus of elasticity and modulus
of rupture respectively. The result revealed that as the plastic/ fibre mixing ratio and board
density increased the tensile strength, MOE and MOR increased, while TS and WA
decreased. Strength properties of composite boards produced with the higher production
variables had higher strength properties and decreased sorption assessment. Bamboo particles
are suitable for the manufacturing of Wood Plastic Composites (WPC) using LDPE.
Nigerian Journal Of Sustainable Environmental Management.
Assessment Of PhysicoMechanical Properties Of Borassus Aethiopum Mart; A Lesser UsedSpecies
Owoyemi J.M., Oyebiyi B.C. And Ogunrinde O.S.
The dwindling supply of timber from the natural forest has necessitated the need to examine
the properties of lesserused
species to determine their suitability for structural applications.
Studies were carried out on the physical and mechanical properties of Borassus aethiopum
mart grown in Iwo Local Government, Osun State, Nigeria. Three stands of Borassus
aethiopum were felled and bulked at 25, 50, and 75% points with samples obtained from
outer and inner portions to determine the property variations. Bending test was carried out to
determine the modulus of elasticity (MOE) and modulus of rupture (MOR) of the wood. The
result showed that the density of the tree species ranged from 514.71 ± 1.53/kg/m3 to 620.00
±5.90 kg/m3 with the outer base portion recording the highest value and the top inner portion
had he least density value. Moisture content of the freshly felled B. aethiopum varied from
30.32±6.47% to 118.18± 5.34%. Findings also revealed that the base outer portion had the
least shrinkage value of 8.47±4.25% whereas the top inner portion had the highest mean
shrinkage value of 10.33±5.39%. For volumetric swelling, base outer portion had the highest
mean value. The mechanical properties result obtained revealed that MOE value ranged from
514.65±58.07 N/mm2 to 9276.59 ±78.20 N/mm2 with the outer base portion had the highest
value and the inner top portion had the least mean value. For MOR, values ranged from
23.13±41.89 N/mm2 to 83.15+65.55 N/mm2. The results obtained showed that Borassus
aethiopum can be used as timber for structural applications in construction companies.
Applied Tropical Agriculture.
Threshold Determination For Chromated Copper Arsenate And Creosote Oil For Termiticidal Treatment Of Gmelina Arborea Wood
Owoyemi J.M. And Olufemi B.
The threshold point of Chromated Copper Arsenate (CCA) and Creosote Oil preservatives for
the treatment of Gmelina arborea wood against subterranean termites was investigated.
Wood samples from 15 years old Gmelina arborea trees were colddipped
with CCA at 4%,
3% and 2% concentration levels while Creosote Oil was used undiluted as well as at 1:1 and
1:3 creosote oilkerosene
mixtures. The treated samples and control were exposed to termite
attack at the timber grave yard, Federal University of Technology, Akure Nigeria for 36
months. The result revealed the efficacy of CCA in the protection of Gmelina wood at three
concentration levels for 36 months. The result revealed the efficacy of CCA in the protection
of Gmelina wood at three concentration levels for the 36month
period with samples
maintaining and ASTM mean visual rating of 10 (sound) at 2,3 and 4% CCA treatment
levels. Creosote oil provided protection for only 12 months period as it recorded heavy attack
and failure at the end of 30 months thereby suggesting a posttreatment
schedule every 12
months for the undiluted creosote oil in order to sustain protection of the wood. It could be
concluded that 3% concentration level is the threshold value for CCA wood treatment while
creosote oil could only be used undiluted for 12 months; its dilution with solvent reduced its
Key Engineering Materials
Assessment Of Inorganic Bonded Paperboards Produced From Kraft And Recycled Newsprint
Owoyemi J.M., Ajayi, B. And Ogunrinde O.S.
Homogeneous cement bonded paperboards were made with recycled newsprints and Kraft
paper with ordinary Portland cement and curing reagent. Boards were produced at the
blending proportions of 100:0, 50:50 and 0:100 respectively and at cement/paper ratio of 1:1,
2:1 and 3:1 respectively. Dimensional movements were evaluated to investigate the effect of
the variables used in board manufacturing before and after exposure to accelerated aging test
procedure. Increase in mixing ratio and blending proportion caused decrease in Thickness
Swelling (TS) and Water Absorption (WA) while TS and WA of the untreated boards were
lower than the accelerated aging treated boards. The dimensional movement of Kraft paper
was higher than that of recycled newsprint before and after accelerated aging treatment. The
strongest and most dimensionally stable board was produced at the highest level of cement/
paper ratio. The preaccelerated
ageing test carried out showed that mechanical properties
were higher 2: 1and 3: 1 paper cement mixing ratios. Kraft paper produced the strongest and
most dimensionally stable board than: recycled newsprint. From this study Kraft paper and
recycled newsprint proved to be suitable for the manufacture of cement bonded paperboard
capable of meeting the needs in core and low cost housing construction.
ISROSETInternational Journal Of Scientific Research In Multidisciplinary Studies
Management Of Nigerian Forest Through Efficient Recovery Of Harvesting Residues
Ogunrinde Olayemi Segun And Owoyemi Jacob Mayowa
Harvesting residue poses a lot of problem especially to the waste management authorities in
Nigeria and as a disturbance to forest floors since it is not being used appropriately. Large
quantity of wood waste is generated daily in harvesting and some other forest management
operations which run into millions of Naira if recycled or properly used. This paper focused
on wood harvesting practices, sources of harvesting residue, the percentage recovery and
their potentials for future usage in other to be able to manage the forest sustainably. Available
resources on this subject were critically reviewed. Findings revealed that large quantity of
wood harvesting residue generated could be used for energy production, ceiling boards,
Charcoal production, fuel wood, briquette and Pharmacognosis. This provides solution to
increasing deforestation caused by overexploitation of the forest due to increasing demand for
forest products thereby reducing pressure on the forest. It is evident however that not all
forest industries, particularly in developing countries currently use harvesting and wood
residues efficiently for energy.