AGRICULTURAL AND BIOSYSTEMS ENGINEERING

The effectiveness of Moringa oleifera seed as a natural coagulant for domestic sewage treatment was investigated in this study. A completely randomized design (CRD) was adopted for the treatment process. The treatments included the control culture (no-Moringa seed), 2 g, 4 g, and 6 g of Moringa oleifera. Physical, bacteriological and chemical properties of domestic sewage were investigated before and after treatment. The turbidity, water hardness, suspended solids, dissolved solids, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) showed reductions while dissolved oxygen (DO) showed some increase indicating that some level of treatment was achieved. There was no significant difference between the pH, BOD and COD obtained for the 2 g, 4 g and 6 g treatments. The study has revealed that Moringa oleifera as a natural coagulant shows potential in the treatment of the domestic sewage.

The potentials of Rattan Cane as a reinforcement material in concrete slabs were investigated. The principal objective was to determine the flexural strength of rattan cane reinforced concrete slabs. The use of steel reinforced concrete façade is gradually becoming unpopular due to the susceptible nature of mild steel to corrosion. This study investigated experimentally the flexural strength of Eremospatha macrocarpa canes reinforced concrete slab in terms of the maximum load the slabs could withstand under axial loading. The research investigated the feasibility of constructing lightweight slabs using rattan cane reinforcements as a replacement for corrosion-prone steel in lightweight construction. Ten slabs of 0.125 m2 and concrete over of 20 mm were constructed for rattan cane and steel reinforcements using the ratio 1:2:4:0.5 for cement, fine aggregate, coarse aggregate and water respectively. The slabs were subjected to incremental third point loading until failure occurred. Deflection and crack width were measured simultaneously at the instance of the first crack and at the point of failure. The results for both types of reinforcements were compared and it showed that the rattan cane reinforced panels failed at 6.53kN load while steel reinforced slabs failed at 12.15 kN. It was observed that steel reinforced slabs had a deflection and crack width of 1.75mm and 0.063 mm respectively while rattan cane reinforced slabs recorded a deflection and crack width of 0.94 mm and 0.002 mm respectively. The flexural strength of 15 N/mm2 and 9.75 N/mm was recorded for steel and rattan reinforced slabs, respectively. The ultimate load and flexural strength of rattan cane were lower than the steel reinforcement, as a result, rattan reinforced slabs can be used in the construction of silo, piggery and cattle barn floors.

An investigation on the effectiveness of Moringa oleifera seed for the treatment of domestic sewage was carried out in 15
litres plastic pots. Completely randomized design (CRD) experimental design was adopted. The treatments included: the
control culture (no Moringa seed), 2 g of Moringa oleifera, 4 g of Moringa oleifera and 6 g Moringa oleifera. Physical,
bacteriological and chemical properties of domestic sewage were investigated before and after treatment. The turbidity
value was reduced drastically for the treatments. Water hardness was reduced from 64.2 mg/l to 36 mg/l for the
treatments. Alkalinity was reduced from 148 mg/l to 114 mg/l for the treatments, total solids were reduced from
1280 mg/l to 1129 mg/l for the treatments, suspended solids were reduced from 384 mg/l to 306.3 mg/l for the
treatments, dissolved oxygen was reduced from 124.8 mg/l to 112.7 mg/l for the treatments, dissolved solids were
reduced from 896 mg/l to 820.3 mg/l for the treatments, and acidity was increased from 0.84 to 2.02 for the treatments.
The pH value was reduced from 9.6 to 7.5 for the treatments. BOD was reduced from 96.5 mg/l to 80.2 mg/l for the
treatments and COD was reduced from 81.6 mg/l to 72 mg/l for the treatments. Generally, the results showed that the
higher the quantity of Moringa oleifera seed applied to sewage, the better the purification of the sewage.

A 1000 kg double walled insulated mobile metallic silo was designed and constructed with two mild sheets of 1mm thickness using sawdust as an insulating material between the metal sheets. The silo has a total height of 1.2m above the ground level with an internal and external diameter of 0.64 m and 0.68 m respectively and resting on a platform which has four wheels attached to it for mobility. A preloading assessment was conducted on the silo to determine the possibility of using sawdust as an insulator in the silo. Comparison was also made between the single walled aluminium sheet silo placed on a platform and the double walled insulated mobile metallic silo to determine thermal performance. Temperature readings were taken 3 times for each time interval for 10 days using a therma waterproof K thermocouple model 232-101. The result showed that the temperature reading was usually low by 8:30am within the double walled silo having a least temperature of 23.9 0 C, while the highest temperature for double walled silo was at 12:30pm with 33.6 0 C and the result also showed that the temperature reading was usually low by 8:30am within the single walled silo having a least temperature of 25.2 0 C while highest temperature for single walled silo was at 12:30pm having a range of 36.6 0 C. The double walled mobile metallic silo moved smoothly on a flat untilled road by pushing without a jolting action and undulating movement. In conclusion, the double walled mobile metallic silo performed better than the single walled silo and has a good thermal property which is suitable for the storage of grains in tropical region for low income farmer.

The study was undertaken to evaluate the performances of an experimental box and platform, as storage structures for white yam tubers (Dioscorea rotundata Poir.). The criteria used for evaluation were the degree of mass loss during storage, tuber sprouting and rotting during the 20 weeks storageperiod: March-June 2015. Measurements of temperatures and relative humidity of the storage environment were taken three times daily during the period. Mass loss in each tuber was measured weekly while sprouts were removed from tubers weekly. Results show that the average temperature and relative humidity in the experimental box were 29.7 °C and 78.6 % respectively, while for the platform, they were 30.7 °C and 76.5 %., respectively. Rotting was completely absent on tubers in both storage approaches. White yam tubers stored in the box exhibited a cumulative mass loss of 9 %, while on the platform, it was15.0 %. The experimental box performed better in respect to mass loss and nutritional composition. IZVLEČEK PRIMERJAVA UPORABE LESENIH ZABOJEV IN PLATOJEV PRI HRAMBI GOMOLJEV BELEGA JAMA V raziskavi je je bila ovrednotena obstojnost gomoljev belega jama (Dioscorea rotundata Poir.) med shranjevanjem v lesenih zabojih in na platojih. Kriteriji za ovrednotenje ohranjenosti gomoljev so bili izguba mase, kalitev in gnitje gomoljev v obdobju 20 tednov, od marca do junija 2015. Meritve temperature in relativne zračne vlage v prostorih hrambe so potekale trikrat dnevno v obdobju trajanja poskusa. Meritve izgube mase vsakega gomolja so potekale tedensko, pravtako odstranjevanje kalečih poganjkov. Povprečna temperatura zraka in relativna vlažnost v poskusnih zabojih sta bili 29.7 °C in 78.6 %, v platojij 30.7 °C in 76.5 %. Gnitja gomoljev ni bilo pri nobenem načinu hrambe. Gomolji belega jama, shranjeni v zabojih, so kumulativno izgubili 9 % mase, tisti v platojih pa 15.0 %. Shramba v zabojih se je izkazala boljša glede izgube mase in hranilne vrednosti gomoljev.

Continuous increase in ceramic ware waste from construction and demolition waste without good management practice has resulted in elevated volume of this waste category. However, utilization of this waste in masonry unit production could be a plausible option to solve this menace, particularly, in its ability to enhance masonry unit compressive strength. In this study, ceramic ware waste was utilized for hollow masonry unit production and three different natural fine aggregate to ceramic aggregate mix ratios of 100:0, 90:10, 80:20 and 70:30 were examined. Furthermore, the cement to total aggregate mix ratio considered was 1:7. Sequel to the process of aggregates mixing, casting, and subsequently demoulding, the masonry units were cured for 28 days prior to inspection for compressive test parameters. Results indicated that masonry unit with natural sand to ceramic waste mix ratio of 80:20 has the highest crushing strength at peak, yield and break point which were 60.903kN, 60.493kN and 53.863kN respectively. The compressive stress at peak and break were 6.57MPa and 6.50MPa in that order and Young's modulus was 0.262GPa. Statistically, there were no significant differences at 95% confidence interval between the aggregate mix masonry units when the compressive strength indices were evaluated. Ceramics ware waste from demolition and construction waste is a suitable co-aggregate in hollow masonry unit production.

Irish potato is a tuberous staple food predominantly grown in Plateau State, a temperate climate. As a result of the high demand
for Irish potato, there is a shortage in its supply in Nigeria. The shortage in its supply could be attributed to climate change and the
fall in the production level. This study sought to establish the potential of a greenhouse (GH) for the production of Irish potato in
the tropics. The experiments were carried out in the rainy and dry seasons of 2015/2016 and 2016/2017. Nicola, Diamant, Batita,
New Seed and Okonkwo varieties of Irish potato were cultivated inside and outside the greenhouse. Thirty seedlings of each
variety were planted using Completely Randomised Experimental Design. Greenhouse performance was evaluated in terms of
air temperature, relative humidity, vapour pressure deficit, yield, stem diameter, stem height and dry matter content. The result of
the analysis of variance revealed that the mean greenhouse and open-field temperature, relative humidity and vapour pressure
deficit differed significantly at 0.01 during the rainy and dry season. The yield and growth data in and outside the greenhouse were
significantly different at 0.01. Diamant, Batista and Okonkwo varieties are recommended for GH production

An African bush mango cracker was modified and fabricated to address the challenges of the
conventional method of cracking nuts which involves striking the nut. The tedious nature of this process constitutes a
major setback which restricts the production to a very small scale. The cracker consists of a frame, cracking table, slider–
crank mechanism, hopper, feed chute, slot, cracking unit electric motor and reduction gear. The machine was evaluated
with respect to throughput capacity and cracking efficiency at five moisture content levels (13, 15, 17, 20 and 25%)
moisture content (MC) dry basis. At 13% MC; the output capacity was 7.13 kg/hr and cracking efficiency was 98% while
at 15% MC; the output capacity and cracking efficiency reduced to 7.04 kg/hr and 96% respectively. Similarly, at 17%
MC; output capacity and cracking efficiency further reduced to 7.02 kg/hr and 95% respectively while at 20% MC; the
output capacity and cracking efficiency were reduced to 6.74 kg/hr and 93% respectively. There was a similar trend when
the test was performed at 25% MC, as the output capacity and cracking efficiency showed a further reduction to 6.50 kg/hr
and 90% respectively. These results were different from the old cracker that had throughput capacity and cracking
efficiency of 4.32 kg/hr and 70% respectively. A significant trend was established which showed that as the moisture
content of the nuts decreases, machine performance increases. Based on these results, drudgery and other hazards
associated with manual cracking of the African bush mango are eliminated, the machine saves time and made processing
of the seeds easier.