Browsing by Author "Olorunnisola, A. O."

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Characteristics of classroom chairs and desks in use in senior secondary schools in Ibadan, Oyo State, Nigeria
(Scholarlink Research Institute Journals, 2010) Adewole, N. A.; Olorunnisola, A. O.
The current status of wooden classroom chairs and desks in use in selected Secondary Schools (SS) in Ibadan was investigated. Fifty-four SS were randomly selected; 12 each from rural and semi-urban, and, 10 from urban areas of Ibadan. Random sampling survey was conducted using structured questionnaire and oral interview and to collect data on chairs and desks types, designs, construction materials and methods, durability and cost factors. Joint features, failure pattern and causes were evaluated via on-the-spot assessments. Simple descriptive statistical tool was used for data analyses. Similar furniture geometry, constructional method and failure mode were noted in rural, semi-urban and urban schools. About 90% of the Schools were using wooden chairs and desks. The two predominant designs were the Single-User (SU), and Multiple-User (MU) types. The production philosophy for both furniture types was one-size-fit all. The SU and MU chairs and desks had a relatively short service life with over 80% of them failing within three months. Poor jointing was responsible for over 69% of the failure. As at December, 2009 a pair of SU and MU chairs and desks cost N2500 and N3500 respectively.
Compability of calamus Deerratus and lactosperma secundiflorum rattan particles with ordinary portland cement
(2007) Adefisan, O. O.; Olorunnisola, A. O.
An investigation was conducted to determine the optimum water to cement ratio for a locally manufactured portland cement for use in wood composites. The effects of pre-processing and calcium chloride (CaCl2) on the compatibility of two rattan canes ( Calamus deerratus and Lacosperma secundiflorum) with cement were also assessed using the compatibility factor (CA) approach. An optimum water: cement ratio of 0.45 was obtained. Generally the two rattan species were compatible with cement. The CA factors increased with increasing levels of CaCl2 concentration (65.2% to 101.5% for C.deerratus and 71.2% to 103.5% for L. secundiflorum at 0 to 3% concentrations). Removal of the silified epidermis (pre-processing) had more significant effect (p< 0.05) on the compatibility of C. deerratus with cement than in the L. secundiflorum species. Also, the particles of the Lacosperma species were more compatible with cement than those of the Calamus species probably due to the anatomy and other variations in the two species.
The development and evaluation of a flat-type wooden incubator
(School of Agriculture and Agricultural Technology (SAAT), Federal University of Technology, Akure, 1998) Ewemoje, T. A.; Olorunnisola, A. O.
"A flat-type, 60-egg capacity incubator was designed, constructed and tested. The incubator differs from existing designs in that the cabinet was made from a 3-ply, 4mm thick interior grade plywood to reduce cost and at the same time enhance heat insulation. Also, two domestic kerosene lanterns were provided to supplement heat generation by three 40 W electric bulbs during electricity outages as commonly experienced in Nigeria.When tested with 30 eggs of a commonly sold chicken breed, incubated at average temperature of 38° C and relatively humidity of 58%, the chicks were hatched within 20 days. Relatively high percentages of fertility and hatchability of 86.2% and 76% respectively, as well as a relatively low chick mortality rate of 18.5% were recorded. "
Effects of cane peeling and aqueous extraction on compatibility of two rattan species with portland cement
(2008) Olorunnisola, A. O.; Adefisan, O. O.
Rattan cane is a relatively abundant lignocellulosic in Africa and Asia that could be used for wood-cement composite production. However, rattans tend to inhibit cement setting. This study investigated the effects of cane peeling and aqueous extraction on maximum hydration temperature (Tmax) and setting time (tmax) rattan-cement- water systems using Calamus deerratus and Lacosperma secundiflorum rattan species. Peeling was done manually to remove the silified epidermis before hammer-milling to obtain cane particles. Portions of the particles were soaked in de-ionised cold (25oC) and hot water (800C) respectively for 30 minutes. Findings showed that aqueous extraction improved the Tmax and reduced the tmax of the rattan-cement mixtures while peeling caused reduction in both Tmax and tmax. The two rattan species seemed more amenable to cold rather than hot water extraction. Peeling, species, aqueous pre-treatment and their interactions had significant effects on the setting time of the rattan-cement mixtures.
Effects of chemical additives on the hydration behaviour of cement composites from calamus and laccosperma canes
(2011) Adefisan, O. O.; Olorunnisola, A. O.
"The effects of calcium chloride (CaCl2) and Magnesium Chloride(MgCl2) on the maximum hydration temperature (Tmax) setting time(tmax) and Time ratio (tR) of Calamus deerratus and Laccosperma secundiflorum particles mixed with Portland cement was investigated. Particles of ratten canes were mixed with cement, water and chemical additives. Hydration tests were performed in thermally sealed thermos flasks while hydration parameters:Tmax and tmax were measured after 24 hrs. The tmax, Tmax and tg ranged between 25.7 to 26.5 hrs,43.1 to 46.6o C and 3.6 to 3.7 respectively without pre-treatment and were between 7.4 to 23.1 hrs,49.3 to 65.7 oC and 1.0 to 3.0 respectively when pre-treated with chemical additives. Findings showed that untreated ratten generally inhibited cement setting probably due to inherent sugar content. Particles of laccosperma canes inhibited cement setting more than those of the Calamus canes. The addition of both CaCl2 and MgCl2 significantly improved the Tmax but reduced the tmax and tr of the ratten-cement mixes. Addition of CaCl2 enhanced the hydration behaviour of the ratten composites more than MgCl2. "
Effects of selected pre-treatment methods on the hydration behaviour of rattan-cement mixtures
(KFRI, 2010) Adefisan, O. O.; Olorunnisola, A. O.
"The influence of clacium chloride (CaCl2), magnesium chloride (MgCl2), hot-and cold-water pre-treatments, and prolonged storage on the hydration behaviour of particles extracted from Calamus deerratus and Laccosperma secundiflorum rattan canes mixed with cement was investigated. While the untreated rattans inhibited cement setting, pre-treatments generally improved compatibility.The addition of chemical additives and aquenous pre-treatments enhanced the compatibility of the rattan-cement composites while peeling of silicified epidermis generally reduced the compatibility parameters. Pre-storage positively influenced the hydration behaviour of the L.secundiflorum composites while it negatively affected the Calamus composites. Statistical analyses revealed that all the pre-treatment methods employed significantly improved the hydration behaviour of the rattan-cement mixes except water and CaCl2 treatments. The compatibility indices based on the maximum hydration temperature (Tmax),compatibility factor (CA), setting time (tmax) and time ratio indices (tR) did not consistently predict the hydration behaviour of the rattan composites. A modified time ratio index based on the threshold temperature (40oC) is proposed for prediction of the hydration behaviour of rattan-cement mixes "
Effects of selected pre-treatment on the setting of cement composite from two rattan species
(2009) Adefisan, O. O.; Olorunnisola, A. O.
"The effects of aqueous extraction and removal of silified epidermis from rattan canes on the maximum hydration temperature (Tmax) and setting time (tmax) of two rattan canes species, Calamus deerratus and Lacosperma secundiflorum, mixed with portland cement were investigated. Tmax ranged from 37.0 to 58.66oC for the C.deerratus and L.secundiflorum composites respectively while tmax was from 3.7 to 26.5hrs and 7.4-25.7 hrs. Aqueous extraction increased the Tmax and reduced the tmax of the rattan-cement mixes while removal of epidermis generally caused reduction in both Tmax and tmax. The two rattan species seemed more amenable to cold than hot water extraction. Although cement extraction improved the tmax of the Calamus-cement composite more than Lacosperma cement composite. Epidermis removal, species, aquenous pre-treatment and their interactions had significant effect on the setting time than of the rattan-cement mixes. "
Factors influencing prospectives uses of ratten canes as furnish for cement composite production
(Forestry Association of Nigeria, 2011) Adefisan, O. O.; Olorunnisola, A. O.
This paper discusses the prospective uses of three readily available ratten canes in southern and western Nigeria namely: Laccosperma secundiflorum, Eremospatha macrocarpa, and Calamus deerratus as furnish for Cement Bonded Composites(CBCs) production. Advantages of utilising ratten canes as furnish for CBC production, limiting factors influencing the development of ratten composites and means of curtailment are examined. Ratten canes are potential furniture for CBC production but will require pre-treatment before use to ensure formation of strong crystalline bond.
Quantitative review of ecosystem services and disservices studies in the tropics
(Scientific Research Publishing Inc., 2019-04) Rutebuka, E.; Olorunnisola, A. O.; Taiwo, O. J.; Mwaru, F.; Asamoah, E. F.; Rukundo, E.
The tropics host about 80% of the planet’s terrestrial species and over 95% of its corals. A well-known tropical forest ecosystem to provide significant global regulating services has declined at a rate of 5.5 M ha per year from 1990-2015, while another region noted an increase per year. There is evidence that tropical region ecosystem services and disservices are the least studied in the world. This study quantified peer-review papers in the tropics, then explored the neglected ecosystem type, service category, assessment mode, applied techniques and choice dependence between ecosystem type, service category, assessment mode and applied techniques. The Google Scholar and Web of Science database were used to collect all ES & ED studies available online from 1960 to December 2017. This review covered 102 countries with 578 articles. The study showed dramatic articles increase in the last three years as more than 50% of articles were published after the year of 2014. The top countries in high articles were Mexico (n = 53), India (n = 43), and Brazil (n = 35). The ES & ED assessment tools/techniques are barely applied in tropics as only social based techniques such as interviews and questionnaire take over 45%, while biophysical tools like remote sensing and GIS appeared only in 20%, InVEST only in 3% while the rest tools are less than 1% even none such as ARIES model. Urban and marine ecosystem types, disservices category and trade-off assessment mode were the least studied. The review concluded that policy analysis ES & ED studies do not reflect the trade-offs and synergy analysis between different services which hinder the development of pragmatic policy and decisions toward ES sustainable management in the tropics. The rampant urbanization in the tropics is subjected to destroy existing ES. Thus, this review highly suggested a high concern of urbanization ecosystem. This study also calls for great academic research to give attention to the tropical rainforest region as most African countries to host such forest have not even a single article on ES & ED.
Strength and sorption properties of cement bonded composites made from calamus deerratus and laccosperma secundiflorum canes
(Tertiary Education Trust Funds, Nigeria, 2012-04) Adefisan, O. O.; Olorunnisola, A. O.
"Two layers rattan cement composites were made from Calamus deerratus and Laccosperma secundiflorum particles using cement: sand:rattan mixing ratios of 1:2:0.2 and 1:3:0.2 and calcium chloride (CaCl2) at two levels 0% and 3% (by weight of cement) and subjected to static bending and sorption tests after production. Results showed that rattan-cement mixes had low moduli of rupture, thickness swelling and water absorption rates but high moduli of elasticity and are suitable for low stress out-door applications. While the Calamus composites generally had low strength and high sorption properties than the Laccosperma cement mixes, peeling significantly reduced the strength properties of the Calamus cement composites possibly due to higher presence of cement inhibitors. Addition of CaCl2 significantly enhanced both the strength and sorption properties of composites made from Calamus and Laccosperma particles "
Trial Production and Testing of cement-bonded particles board from rattan furniture waste
(Society of Wood Science and Technology, 2002) Olorunnisola, A. O.; Adefisan, O. O.
An investigation was conducted on the use of rattan (cane) furniture waste as furnish material for the manufacture of cement-bonded particleboard (CBP). Laboratory scale CBPs were fabricated from hot water pretreated chopped strands of mixed rattan waste obtained from rattan furniture workers in Ibadan, Oyo State, Nigeria. Three-layered boards of 6-mm thickness were made comprising coarse core and tine surfaces at two density levels of 1,050 kg/mi and 1,200 kg/m3, three CaCl2 concentration levels of: 2.5%, 3.0% and 3.5% and using Portland cement-cane mixing ratios of 2.5:l .0, 2.75: 1 .0, 3.0: 1 .0, and 3.25: 1 .0. After board manufacture, ASTM D 1037 (1998) test procedures were employed to obtain strength and moisture absorption properties. Average properties for bending modulus of rupture (MOR) and modulus of elasticity (MOE) of the boards ranged between 0.5 and 1.6 N/mm2, and 480 and 3,563 N/mrn2, respectively. Mean thickness swelling (TS) and water absorption (WA) values ranged between 1.1 and 8.6%, and 31 and 51%, respectively. Analysis of variance showed that except for MOE, the levels at which the density, CaCI2 concentration, and cement-cane mixing ratio were used and their interaction had no significant effects on properties of the board. The relatively low strength and water resistance properties of the boards make them suitable only for use in low stressed interior applications. Further investigations are, however, required on the effects of different cane preparation procedures and other fabrication variables on board properties. This is necessary to provide the guidelines required to adequately control the fabrication process and optimize material properties.