1 |
Author(s):
Ishidi, Y.E., Bello, K.A., Adamu, I.K..
Page No : 1-12
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EFFECT OF PLANT EXTRACTS AND CITRUS/BANANA PEELS MORDANTS ON PHYSICO – MECHANICAL CHARACTERISTICS OF VEGETABLE AND CHROME TANNED LEATHER
Abstract
The increased cases of allergic reaction against synthetic dyes and the changing environmental conditions, have stirred up the urgent need for an environmentally safe dye. In the current study, six different plants were used for the experiments: Mango (Mangnifera indica), Hibiscus sabdariffa, Savanna mahogany (Khaya senegalensis), Red onion (Alluim cepa) and Annatto (Bixa orellea). The extraction was done using different solvents, namely, chloroform, acetone, ethanol, methanol and water (distilled). The crude extract was used to dye vegetable and chrome tanned leathers with plantain/citrus peels as sources of mordant. Four different microbes were used to ascertain the microbial activities of leathers treated with the plant extract. The results showed that dyes from plant cannot replace synthetic dyes due to low percentage yield of the plants. It was also established that plant extracts do not affect the tensile strength of the finished leather. The use of plantain and citrus peels as a mordant for leather dyeing was established, except for citrus on vegetable tanned leather which showed burning effect.
2 |
Author(s):
Mohammed, K., Yahaya, S..
Page No : 13-20
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FEASIBILITY STUDY ON SURFACTANTS REMOVAL FROM PERSONAL CARE PRODUCT WASTEWATER USING SINGLE-STAGE FOAM FRACTIONATION
Abstract
This paper presents a feasibility study on pre-treatment of personal care products (PCP) industrial effluents. The study employed single-stage foam fractionation as pre-treatment method. Three synthetic waste streams: shampoo-with-silicon, sh(+si), shampoo-without-silicon, sh(-si), and hair dye (ec) were used in the study. Chemical oxygen demand (COD) and foam measurements were conducted on pre-treated samples to determine carbon and surfactant removal efficiencies, respectively. COD removal efficiency > 90% was achieved in all the three waste streams. However, foam removal efficiency > 90% was only achieved in shampoo-based waste streams at low air flow rates. Results obtained indicated that foam fractionation is effective in selective removal of surfactants from shampoo-based waste streams at airflow rate lower than 3 L/min.
3 |
Author(s):
Ogork, E.N., Suleiman, J.A..
Page No : 21-27
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ASSESSMENT OF THE EFFECTIVENESS OF VARIOUS CURING METHODS ON THE QUALITY OF CONCRETE
Abstract
This paper evaluates the effectiveness of curing methods on the quality of concrete. Concrete grades 20 and 30
cube specimens were prepared and cured using five curing methods; submerged, jute sack, sprinkling,
polythene covering and atmospheric curing for 3, 7, 14, 21 and 28 days and tested in compression. Water
absorption test was also conducted on cubes cured for 28 days using the five curing methods. The concrete
compressive strengths for the various curing methods were also modeled from concrete compressive strength
for submerged curing using Minitab statistical software based on linear regression technique. Results showed
that submerged curing is the most effective curing method, followed by jute sack, sprinkling, polythene
covering and atmospheric curing. The compressive strength models were developed with R2 values of 0.981,
0.950, 0.928 and 0.758, respectively and could be used to predict the concrete compressive strength of
members cured using various techniques in construction sites.
4 |
Author(s):
Abdulwahab, M.T., Uche, O.A.U..
Page No : 28-34
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UNCERTAINTIES AND RELIABILITY ANALYSIS OF REINFORCED CONCRETE FOLDED PLATES
Abstract
The study presents reliability assessment of reinforced concrete folded plates with deterministic and stochastic design carried out in accordance with Eurocode 2. This was based on the First Order Reliability Method (FORM) using FORM 5. Limit state equations for reinforced concrete folded plate subjected to bending, longitudinal stress and deflection were derived and their implied reliability levels evaluated. All basic design variables involved are treated as random variables with their statistical characteristics adopted from the literature. The results showed that safety index decreases with increase in load ratio which was as a result of diminishing strength and largely depends on their variable parameters. It was also observed that both bending and longitudinal stress are safe at load ratio of 0.1 to 0.6 with safety indices ranging from 3.20 to 4.26 and probability of failure of 10-5 while it becomes critical at load ratio of 0.8 to 1.0 which correspond to safety indices of 2.51 to 2.84. For deflection mode of failure, the structure is safe at all load ratio. The reliability assessment of the folded plate structure is unavoidable in order to ensure safety and minimum investment in design and construction.
5 |
Author(s):
Dalha, I.B., Mohammed, U.S., Abdulsalam, M., Lawan, I..
Page No : 35-43
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PERFORMANCE OF A MODIFIED PULSE SHELLER UNDER SELECTED MACHINE FACTORS
Abstract
Pulse sheller was designed with a view to shelling different varieties of leguminous crops such as groundnut, cowpea, among others. The size of the existing machine was modified resulting in the re-design of virtually all components for pulse shelling. The sieve was initially designed with round holes which were suitable for cowpea shelling but not groundnut and an oval shape was redesigned for its shelling. The clearance adjuster was also modified to facilitate shelling of different crops varieties. The performance was evaluated using a local groundnut variety - “Bahaushiya”. A combination of four cylinder speed levels; 130, 140, 150 and 160 rpm and three concave clearances; 19, 21 and 23 mm, were used for the performance evaluation of the modified pulse shelling machine. The effects of some selected machine factors; cylinder speed and concave clearance, were assessed statistically in a Randomized Complete Block Design (RCBD) and Least Significant Difference (LSD) was employed to assess the effects of parameter levels. The optimum performance of the modified machine using groundnut crop was found at a cylinder speed of 160 rpm and a 21 mm concave clearance. These gave an output capacity, shelling efficiency, cleaning efficiency, scatter loss and damaged grains of 232.85 kg/h, 94.45, 96.95, 5.82 and 17.44 % respectively. The cylinder speed was found to have positive linear trends with the all performance indices at various concave clearances except grains damage. The results revealed that cylinder speeds significantly affected all the performance indices except output capacity while concave clearances have no significant effect on output capacity and shelling efficiency
6 |
Author(s):
Ogork, E.N., Dayyabu, A..
Page No : 44-51
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SAFETY LEVEL ASSESSMENT OF EXPANSION JOINTS IN REINFORCED CONCRETE SLABS TO TEMPARATURE VARIATIONS.
Abstract
This paper presents the safety level assessment of expansion joints in reinforced concrete slabs subjected to temperature variations taking into consideration the BS 8110 (1997) code provision of 25 mm expansion joint at every 30 m of the slab. Reliability analysis of the expansion joint in reinforced concrete slab to ascertain its level of safety was carried out using first order reliability method (FORM).Sensitivity analysis was carried out by varying the change in temperature and length of the concrete slab. The results showed that there was a general decrease in safety index from 18.60 to 9.46 with increase in temperature change from 5 to 20oC. The safety index of the expansion joint in slab is conservative and sensitive to temperature variation and the length of slab.
7 |
Author(s):
Abdulsalam, M., Isiaka, M., Dalha, I.B., Dalhat, M.K..
Page No : 52-66
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PERFORMANCE EVALUATION OF COMPUTER-BASED SUITABLE FIELD WORKDAYS MODEL
Abstract
Maximum utilization of power and machinery requirement for farm production system depends on the accurate
information on suitable field workdays. This study focused on determining the accuracy and performance of the
computer based suitable workdays model developed for estimating the available workdays for tillage operations in the
selected locations in Northern part of Nigeria. Normally, amount of moisture stored in the soil and rainfall amount
were the criteria used for segregating the good and bad tillage workdays. Based on these criteria, field soil moisture
monitoring was conducted for period of 30 days during rainy season and recorded as the field measured soil moisture
data. Also, five (5) years (2008-2012) rainfall data were collected from the IAR meteorological station and used as the
field measured rainfall data. The simulated soil moisture and rainfall values using the computer based suitable
workday’s model and the field measured soil moisture and rainfall data were subjected to statistical analysis. Field
measurements of soil moisture were conducted and the results were used to evaluate the performance of the SFWD
computer model developed. The results were subjected statistical analysis and results show that the R2, RMSE, CRM,
and EF were 0.9297, 0.138, 0.031 and 0.797 or 79.7% respectively for the comparison of the simulated and observed
soil moisture. The result of the paired t-test shows that the differences were not significant at 5% probability level. The
simulated rainfall amount fit best with the 2010 rainfall data with R2, RMSE, CRM and EF value of 0.8699, 0.3411,
0.0005 and 0.7125 respectively. Generally, the differences in the simulated and measured rainfall of year 2008 to 2012
were not significant at 5% level of probability. The study guides farm machinery managers in making wise decisions
with respect to when, where and how to perform desired operations.
8 |
Author(s):
Onchiri, R.O., Sabuni, B.W 2., Tsado, T.Y., Mwangi, D.K..
Page No : 67-78
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EFFECTIVENESS OF MOLTEN PLASTICS AS AN ALTERNATIVE BUILDING CONSTRUCTION MATERIAL
Abstract
This paper presents the research findings on use of molten plastics as a binder in making building blocks. Laboratory experimental analysis method was adopted for the research study. Sample blocks were made from molten plastics and quarry dust in different proportions. The mixture was subjected to pressure so as to achieve reasonable compaction. The mix propor-tions were 15:85, 20:80, 30:70, 40:60 50:50, 60:40, and 70:30 of plastic to quarry dust. Laboratory tests carried out included compressive strength, density and water absorption. Results showed an increase in strength as the proportion of the molten plastics increased to an optimum value of 10.47N/mm2 at 40% of molten plastic contents, which is higher than the cement-quarry dust. The strengths were comparable to that of designed block strength made from quarry dust and cement in the ratio of 1:6 and 2:4 with water-cement ratio of 0.5, which gave 4.00N/mm2 and 1.72N/mm2. The water absorption decreased with increase in plastic content. Values of water absorption capacities obtained from of all the blocks were between 0.22% -7.60% which are below the standard maximum value of 12%. This implies that the volume of fine content is appropriate and the desired strength of the block can be achieved. From the forgoing, it can be con-cluded that molten plastics is an effective alternative binder in the construction industry, thus managing solid waste.
9 |
Author(s):
Bukata, B.B..
Page No : 79-88
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APPLICATION OF DSTATCOM FOR POWER QUALITY IMPROVEMENT IN A MICROGRID
Abstract
The authors have examined a simulation study on the application of distribution static compensator (DSTAT-COM) in a microgrid to solve power quality (PQ) problems. Integrating renewable energy sources (RES) to realise microgrids at distribution corridor further aggravates customer’s power quality, which is often defined asany deviation from the fundamental, of either voltage or frequency signal. Traditionally, the solution is sought through careful design of proportional-plus-integral (PI) controllers for DSTATCOM interfaced mi-crogrid network. The PI parameters would normally involve internal current and external voltage control loops, as well as the DC-link voltage regulator. In this paper, modeling and simulation ofDSTATCOM based 9MW wind turbine generators (WTG) representation of microgrid system is implemented in Simulink’s Sim-PowerSystems for solving two distinct PQ problems: that is, voltage sag and voltage swell. The results ob-tained conformed to the requirement of the IEEE Standard 519 of 1992.
10 |
Author(s):
ANIBUDE, E.C, JAHUN, R.F, ABUBAKR, M.S..
Page No : 89-97
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EFFECTS OF PRESSURE AND HEIGHT ABOVE TARGET ON DISCHARGE RATE, SWATH WIDTH AND DROPLET SIZE FOR AN ANIMAL DRAWN HYDRAULIC SPRAYER
Abstract
An animal drawn hydraulic boom sprayer of 100 liters tank capacity was developed using locally available materials and its performance evaluated. In field testing, discharge rate (ml/min), swath width (m) and droplet size 𝜇𝑚 (vmd) were used as performance indicators. And operating pressures (15, 30 and 45 psi) and heights above target (30, 40 and 50 cm) as independent variables. Results revealed that the effects of operating pressures and heights above target were found to be of great influence to the discharge rate, swath width and droplet size statistically. Effective field capacity of 1.04 ha/hr and 89.6% field efficiency was determined. Comparing the results with what was obtained using the manually operated knapsacks sprayer represents 59% and 64% increase in discharge rate and swath width respectively. The finding of the research study presented in this paper could be used to boost agricultural mechanization during the application of liquid chemical on field crops.
11 |
Author(s):
Musa, N.M., Ma'aruf, A, Umar, B.A.
Page No : 98-105
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PERFORMANCE OF RECYCLED COARSE AGGREGATE (RCA) CONCRETE IN NORMAL AND ACIDIC ENVIRONMENT
Abstract
This paper presents the results of an experimental investigation carried out to study the effect of acidic environ-ment on recycled coarse aggregate (RCA) concrete, in which the natural coarse aggregates were replaced by weight with 0%, 50% and 100% RCA. To study the performance of RCA concrete in acidic environment, com-pressive strength test at 7, 14 and 28 days before immersion in acid, Weight loss assessment after immersion in acids at interval of 7 days and compressive strength loss assessment after immersion in 5% hydrochloric acid (Hcl) and sulfuric acid (H2SO4) mediums at interval of 7 days for 28 days were carried out. The results indicate that the compressive strength and weight decrease with increase in RCA replacements. Generally, specimens containing 50% RCA replacement shows a comparable performance with control specimens in acidic environ-ment.