Olawale U Dairo | Federal University of Agriculture, Abeokuta. FUNAAB (original) (raw)

Papers by Olawale U Dairo

UNIOSUN Journal of Engineering and Environmental Sciences, Sep 30, 2022

A variable amplitude and frequency of mechanical vibrating container working on cam and follower ... more A variable amplitude and frequency of mechanical vibrating container working on cam and follower mechanism have been established. This study carried out a performance evaluation on the utilization of the established vibrating container for potential application in slowing down sprouting in yam. The vibrating container is electrically operated and a variable speed electric motor of 15, 000 rpm was selected for the machine. The performance parameters of the established mechanical vibrating container investigated were percentage maximum displacement and velocity of the vibration at different combined stages of amplitudes and frequencies. The percentage achievable maximum displacement of vibration measured for theoretical amplitude of cams of 5

CERN European Organization for Nuclear Research - Zenodo, May 6, 2022

Mechanical Engineering for Society and Industry

This research investigated the role of silica on palm kernel shell (PKS) as friction lining mater... more This research investigated the role of silica on palm kernel shell (PKS) as friction lining materials in automotive brake pad production. The friction materials were crushed, milled and sieved into four different particle sizes of 100, 150, 200 and 350 µm. The formulations weight percentages employed included Resin (20%), steel slag (15%) and carbon black (5%) while palm kernel shell and silica were varied for each particle size. Individual formulation was mixed for about 10 minutes until formation of homogeneous mixture. Homogeneous formulation A, B, C and D respectively, was compacted into mould and later sintered at 150 oC for 10 minutes in electric furnace and subsequently treated to enhance quality. Produced samples were characterized and evaluated for surface hardness (SH), compressive strength (CS), flame resistance (FR), oil absorption (OA), water absorption (WA) and wear rate (WR). The particles were also characterized using Scanning Electron Microscope. The results reveal...

CERN European Organization for Nuclear Research - Zenodo, Mar 25, 2022

Early sprouting of yam tuber is a typical problem during storage resulting into weight losses, de... more Early sprouting of yam tuber is a typical problem during storage resulting into weight losses, deterioration, shrinkage and reduction in quality. This research work therefore carried out investigation on the application of vibration technique for the control of physical properties of yam (Dioscorea spp.) sprouts during storage in FUNAAB, Nigeria environment. The physical properties (length, number and weight of sprout, number of leaves and weight of roots) of the yam sprouts were determined for 140 white yam tubers. The yam tubers were divided into 108 experiment and 32 as control. The factors of the experimental design examined were frequency, amplitude and time of vibration of low (1-5 Hz, 5 mm and 3 minutes), medium (60-100 Hz, 10 mm and 10 minutes) and high (150-200 Hz, 20 mm and 15 minutes) respectively; weight of yam tuber of two levels of small (0.1-2.9 kg) and big (3.0-5.0 kg) were also considered. The tubers were stored for ten weeks after vibration, the physical properties of the yam sprouts were observed and records were taken every week. All the physical properties of yam sprouts examined followed the same trend. It was discovered that as the frequency, amplitude and time of vibration were increasing, the physical properties of the yam sprouts studied were decreasing significantly at p < 0.05 for both weight of yams between 0.1-2.9 kg and between 3.0-5.0 kg. The results revealed that mechanical vibration significantly help in slowing down sprouting in yam tubers.

CERN European Organization for Nuclear Research - Zenodo, 2020

Sustainable Engineering and Innovation, 2022

At a high frequency of vibration; the cam of a vibrator always encounters the issue of jamming or... more At a high frequency of vibration; the cam of a vibrator always encounters the issue of jamming or the follower rolling off or losing contact with the cam when the appropriate design is not carried out. This study, therefore, developed the shape of the cam profile of mechanical yam vibrator using cycloid motion in the South. Displacement equations from the base circle to the cam profile were developed to obtain the shape of the cam using cycloid motion. A vibrometer was used to evaluate the developed 5 mm, 10 mm, and 20 mm cam sizes installed in a mechanical yam vibrator. The maximum displacement recorded for 5 mm, 10 mm and 20 mm cam sizes were 4.47 mm, 8.71 mm, and 14.54 mm respectively for low (1 – 5 Hz) frequency; 4.58 mm, 8.84 mm and 16.34 mm respectively for medium (60 – 100 Hz) frequency; and 4.66 mm, 9.09 mm and 17.30 mm respectively for high (150 – 200 Hz) frequency. This study shows that a cycloid cam would operate smoothly at low, medium, and high frequencies of vibration ...

Mechanical Engineering for Society and Industry, 2021

Industrial excess heat is a largely untapped resource that has the potential for external use tha... more Industrial excess heat is a largely untapped resource that has the potential for external use that would be beneficial to the cement industry. Therefore, this work studied the excess heat utilization for the optimization of production cost in a cement plant within a period of three years. The study of plant layout in the selected plant in Nigeria (Ewekoro II Cement Plant of 200 tonnes/hour) was carried out to identify areas where excess heat is generated. The temperature and static pressure of precalciner, kiln, and cyclone were taken using a temperature probe, pitot tube, digital manometer, and light-emitting diode temperature reader. These parameters were used to obtain the mass flow rate and heat transfer needed for the heat energy analysis of the system. The kiln was maintained at constant tonnage per hour through a clinker truck weighed using the weighbridge. The result showed that the heat generated from the kiln was 577,640,260 MJ/hr. through excess air draft of 780,000 m3/hr...

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020

The influence of torrefaction pretreatment on the properties of briquettes made from the blends o... more The influence of torrefaction pretreatment on the properties of briquettes made from the blends of sawdust (SD) and cassava peel (CP) was studied. These feedstocks were combined at mixing ratios of 90/10, 70/30, 50/50, 30/70 and 10/90 for untreated and torrefied conditions. The physical and combustion properties were determined using standard methods. Results obtained at all mixing ratios show that the fixed carbon, volatile ignitability, and calorific value increase with the increase in the torrefaction temperature. Further results show that the physical and mechanical properties yield better result through water preconditioning. This work established that high quality briquettes with improved strength and caloric value could be produced from discarded SD and torrefied CP.

Journal of Failure Analysis and Prevention, 2019

Incorporation of roller presses in the grinding circuits of cement manufacturing plants was borne... more Incorporation of roller presses in the grinding circuits of cement manufacturing plants was borne out of the dire need to reduce the power consumed by ball mills in its finish grinding process. This study evaluated the wear phenomena of a roller press installed in a cement plant. Two improvised wear measuring devices (IWMDs) were constructed on a laboratory scale with chevron lines created on each of the rollers. One of the IWMDs had 1.00% chromium and 0.20% molybdenum exhibiting the exact properties of the existing roller press. The other IWMD had 1.10% chromium and 0.22% molybdenum. The IWMDs were subjected to grinding operation with the same raw material of sized media fed at 0.2 tonnes/h for a continuous grinding period of about 6 h per day. Wear measurements were taken on the lines monthly for trending and up till the end of 733 h test running. The chevron lines on the IWMD with Xuper 646 XHD chipped off after 17.5 h of operation, while that with chevron lines made with AbraTec 6710 XHD was in operation for a cumulative period of 733 h within 7 months. Results on the AbraTec 6710 XHD model showed a maximum of 0.04 mm/tonne average wear within a span of 7 months compared to the chipped-off lines and an average wear rate of 1.75 mm/tonne on the Xuper 646 XHD IWMD having characteristics of the existing equipment. The AbraTec 6710 XHD IWMD indicated its suitability for clinker-limestone grinding roller press compared with Xuper 646 XHD.

International Journal of Integrated Engineering, 2018

Computerized Maintenance Management System (CMMS) is a tool tailored to support maintenance busin... more Computerized Maintenance Management System (CMMS) is a tool tailored to support maintenance business functions of production systems. Market available CMMS software programs seldom meet the needs of each organization's peculiar maintenance functions. Therefore, this work investigated the effects of CMMS on a cement production plant. The materials used included a Computer and Networking system and maintenance software. Preliminary study via interview among the relevant maintenance staff members of the plant was conducted to identify critical plant assets. Critical assets considered under this study are Limestone Crusher (LC), Cement Mill (CM) and Kiln (KI) among others identified. Key Performance Indicators (KPIs) such as Plant Reliability Factor (RF), Number of Stoppages for Incidents (NSI) and Production Losses (PL) were used as basis for the evaluation which covered period from year 2013 to 2015. The result obtained from this implementation showed that RF for LC,

The effects of alcohol seed ratio (0.5, 1.5 & 2.0) and initial catalyst amount (0.5, 1.0 & 1.5%) ... more The effects of alcohol seed ratio (0.5, 1.5 & 2.0) and initial catalyst amount (0.5, 1.0 & 1.5%) on the in-situ production of biodiesel from raw Jatropha Curcas seed were studied and evaluated at a reaction temperature of 60 0 C and reaction time of 120min using the Central Composite experimental Design. Initial catalyst amount and alcohol seed ratio were found to have significant (P<0.05) effects on the yield of biodiesel produced. Initial catalyst amount was the more important factor and had a positive influence on the yield than alcohol seed ratio which does not significantly affect the yield as a single factor. Due to formation of by-products (soaps) caused by excessive amount of catalyst and excess alcohol leading to difficult ester separation from glycerol, there was a general reduction in Jatropha Curcas ethyl-ester as levels of catalyst and alcohol seed ratio increased. A second-order quadratic model was obtained to predict the yield as a function of both factors. The model predicted well the observed data with a R 2 value of 0.985 and a non-significant Lack-of-Fit (P<0.05). The biodiesel obtained, compared favorably with the ASTM D6751-02 standard for biodiesel.

This paper investigates the effect of relative volatility of beer obtained from the fermentation ... more This paper investigates the effect of relative volatility of beer obtained from the fermentation of cassava mash on the design of distillation column using developed Java based simulation software. The simulation was done by varying the relative volatility as an input parameter to the developed software and changes in the number of trays in the column and the column height were studied. Varying the relative volatility between 1.3 and 2.2 at an interval of 0.1, the number of trays decreases from 10 to 4 (approximately) and the column heigth decreases from 5.375 to 2.411m. The result indicated that decrease in the value of column heigth and number of trays with increase in relative volatility shows the effect of relative volatility on the corresponding number of trays and the column height of distillation column that would give the highest purity of ethanol.

Cassava is a multipurpose crop for man and livestock. Cassava starch is an ingredient in the manu... more Cassava is a multipurpose crop for man and livestock. Cassava starch is an ingredient in the manufacture of dyes, drugs, chemicals, carpets and in the coagulation of rubber latex. The way forward is the design of appropriate mechanical device and system for sieving dried cassava flakes (Garri). This project seeks to design and fabricate an improved garri sifting machine. There is need for the development of commercial scale garri sifting machine where the roasted garri can be properly monitored. Some design considerations used in this project include efficiency, portability, and safety of operations. Adequate care of chemicals present in cassava juice was considered in selecting materials for fabrication of the machine. The machine was damped to reduce noise pollution during its operation. The machine runs on a single phase 1 HP. electric motor at a speed of 1400 RPM. The result obtained from performance evaluation test showed a sieving efficiency of 92.5% as compared with machine e...

Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in undergr... more Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground carbon- based resources. This has necessitated the search for alternative fuel from renewable sources. Waste cooking oil (WCO) has been identified as a renewable resource from which biodiesel can be produced. Methanolysis of WCO to obtain WCO biodiesel was employed via potassium hydroxide (KOH) catalyst. ASTM and EU standard fuel test performed on the WCO biodiesel gave reasonable result as alternative biodiesel fuel. The effect of KOH concentration on WCO biodiesel is investigated, with a view to identifying the catalyst concentration corresponding to optimal yield. Three replicated methanolysis experimental runs were employed out for each of the KOH concentration 0.5%, 0.75%, 1.0%, 1.25%, 1.50%, 1.75%, 2.0 % and 2.5% (by mass of WCO) under identical typical methanolysis reaction condition of 60oC temperature, 60 minutes and 22% methanol (by mass of WCO). Results obtained gave 91.1...

Cost of biodiesel produced from virgin vegetable oil through transesterification is higher than t... more Cost of biodiesel produced from virgin vegetable oil through transesterification is higher than that of diesel fuel and cost associated with conventional technique (batch reactor) is enormous. To minimize the cost, waste cooking oil and domestic blender, which was modified as reactor was explored as feedstock and reactor respectively. Laboratory scale quantities of methyl ester of WCO (MEWCO) were synthesized and characterized as diesel fuel. KOH was employed to catalyse the transesterification process of WCO with methanol using 100g WCO, 22.0g methanol, 1.0% KOH at 60oC reaction temperature and 60 minutes reaction time. The process was replicated and average results evaluated. A moderately high yield (96.6 0.45 wt. %) of WCOME was obtained under classic reaction condition. The fuel properties of WCOME measured were found to fulfil both ASTM D6751 and EN 14214 biodiesel standards. In addition, the fuel properties were analogous to other waste cooking oil methyl ester produced by ot...

Open Journal of Soil Science, 2013

This paper reports the experimental investigation of the agronomic performance of okra under vari... more This paper reports the experimental investigation of the agronomic performance of okra under various quantities of both sawdust and trash mulches. The location of the field was the research farmland of the Federal Polytechnic Ado Ekiti Nigeria; Lat 6˚N and Long 16˚E. The experimental design used was complete randomized design with 6 treatments on both specimens. The experiments were repeated the following year on the same plot but with transposed plot allocation. Soil moisture loss from uncovered plot was with the highest value dropping to less than 2 per cent. It was followed by that of trash plot and the lowest loss was on sawdust mulched plot. The number of leave formed by okra on sawdust, trash and no mulch plots was 43, 36 and 27 respectively while maximum girth diameter was 37 mm in both trash and sawdust covered plots but okra plant on control plot attained only 26 mm diameter. Fruit yield were almost similar to trash and sawdust mulched okra having 7.5 and 7.6 Tonnes/Ha respectively while control plot recorded 5.2 Tonnes/Ha. The ash content of dry matter of sawdust, trash and no mulched plants was 0.25, 0.20 and 0.17 kg respectively. It was concluded that sawdust could perform as much as the traditional trash materials commonly used in Southwestern Nigeria. Also, sawdust was a good material for conserving soil moisture.

International Journal of Food Science & Technology, 2008

In this study, a laboratory convective hot air dryer was used for the thin layer drying of blanch... more In this study, a laboratory convective hot air dryer was used for the thin layer drying of blanched yam slices and experimental moisture ratio was compared with Newton, Logarithmic, Henderson and Pabis, modified Henderson and Pabis, approximation of diffusion, modified page 1, two-term exponential, Verma et al. and Wang and Singh models. Among all the models, the approximation of diffusion model was found to satisfactorily describe the kinetics of air-drying of blanched yam slices. The increase in air temperature significantly reduced the drying time with no constant rate period but drying occurs in falling rate period. The effective diffusivity values varied between 7.62 • 10)8 to 9.06 • 10)8 m 2 s)1 and increased with increase in temperature. An Arrhenius relation with an activation energy value of 8.831 kJ mol)1 showed the effect of temperature on moisture diffusivity.

Journal of Agricultural Engineering Research, 1994

ABSTRACT

Ethanolysis reaction is not as common as methanolysis in comparison to intensive studies on use o... more Ethanolysis reaction is not as common as methanolysis in comparison to intensive studies on use of methanol for trans-esterification. Raw castor oil bean seed kernel at moisture content of 4.68 % (db) was subjected to in-situ trans-esterification in a batch processor with ethanol as the solvent and sodium hydroxide as the catalyst. Response surface methodology (RSM) and a 3-level, 4 factor central composite design (CCD) were applied to evaluate the main and interactive effects of reaction time (30 -120 min), alcohol-seed weight ratio (0.5 -2.0), catalyst amount (0.3 1.5%) and reaction temperature (40 - 65°C), on yield of castor ethyl-ester, as well as the optimization of the process factors using Taguchi optimization technique. The yield of Castor ethylester ranged from 0.565 to 0.976 obtained from about 400 g of ground seed with expressible oil content of 37.92% and acid value of 10.65 mg KOH/g while raw glycerol ranged from 43.91 to 67.21 g and dried seed cake from 190.31 to 248.09 g for all levels of experimental factors. A quadratic polynomial equation consisting of significant process factors at 95 percent confidence level obtained by multiple regression analysis predicted an optimized yield of 99.5 percent at reaction temperature of 60.330C, catalyst rate of 1.31% weight of castor seed, alcohol-seed weight ratio of 0.50 and reaction time of 82 min. Measured properties of the castor ethyl-ester are viscosity(5.78mm2/s), pour point (-21.50C), flash point (177.120C), calorific value (47.76MJ/kg), acid value (0.34 mg KOH/g) and cetane number (48.73). Second order response surfaces and contour plots obtained from the model revealed that increased catalyst amount, reaction time and temperature all increased the yield of castor ethyl ester, while increased alcohol-seed weight ratio decreased the yield. The catalyst amount and the reaction time were the two most effective factors on yield while reaction temperature had less effect. The interactions of the alcohol-seed weight ratio with other factors (catalyst amount, reaction temperature and reaction time) were more significant than its main effect on the yield. A comparison of yield obtained from Taguchi orthogonal L9(Y'4) confirmatory experiments and the yield from quadratic equation at various factor levels revealed that the model predicted accurately the yield of castor ethyl-ester within the experimental range using a paired t-test at 99.5 percent confidence level. A mini processing plant of 10Llbatch capacity was designed, fabricated and tested at optimum variable conditions obtained from the laboratory experiments. The biodiesel produced from ground castor oil bean seed using ethanolysis rather than traditional methanolysis during this study met the requirements of ASTM standard 06751-02 but specific gravity(0.932 g/crrr'), about 5.9% higher than the ASTM standard (0.88) confirming that biodiesel produced from castor bean seed using the in-situ technique can be used as replacement fuel for fossil diesel.

Yam tubers loss weight during storage and prolonged storage can reduce tuber quality and quantity... more Yam tubers loss weight during storage and prolonged storage can reduce tuber quality and quantity. This study investigated the application of vibration technique for the control of physical properties of yam tubers during storage. Measurements were conducted on the physical properties of the tubers: weight loss, shrinkage of the middle diameter, shrinkage of the length, top and bottom diameter, on 108 tubers treated and 32 tubers untreated (control). The factors of the experimental design were three levels of vibration frequencies, i.e. low (1 – 5 Hz), medium (60 – 100 Hz) and high (150 – 200 Hz), amplitudes of low (5 mm), medium (10 mm), and high (20 mm), and durations of low (5 minutes), medium (10 minutes) and high (15 minutes). Tuber weights were classified as small (0.1 – 2.9 kg) and large (3.0 – 5.0 kg). The tubers were stored for ten weeks after vibration, and their physical properties were measured every week during the storage period. Our study demonstrated that as the freq...