1 |
Author(s):
Falalu, R.J., Jatau, J.S..
Page No : 1-12
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DESIGN AND PRODUCTION OF SINGLE-THROW NODULAR CAST IRON CRANKSHAFT
Abstract
The design, casting and mechanical test of single-throw ductile cast iron crankshaft is presented. Sand casting technique, with side gating system (riser contact in cope) was adopted. The ductile cast iron material was produced by inoculating molten iron (which contains sufficient amount of silicon) in the ladle. This was accomplished by adding small amount of magnesium in the form of magnesium ferrosilicon alloy (5% Mg, 45% Si, rest iron) into the ladle melt which resulted to nodularization of the free graphite carbon. The inoculants were introduced into the melt by sandwich method. Crankshaft was then cast at different pouring temperature and time. Mechanical properties test was conducted on the as- cast and annealed samples. Results show that best quality crankshaft can be produced at pouring temperature and time ranges of 1400- l415°C and 7-12 seconds respectively. Values of tensile strength, hardness and percent elongation for the as-cast samples were on the average found to be 620 N/mm2, 300BH and 4.5% respectively while for the heat treated samples the corresponding values were 500 N/mm2, 205BH, 12%. Also impact strength was found to be 13.0 J. On comparison, the mechanical properties were found to be in good agreement with that of forged/machined steel crankshaft material (773 N/mm2, 18% and 225-235BH) with even better hardness property in the as-cast condition.
2 |
Author(s):
Oricha, J.Y, Jimoh, B., Mahmud, D..
Page No : 13-22
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RELIABILITY AND OUTAGE COST ASSESSMENT OF 33KV FEEDERS IN KADUNA METROPOLIS OF NIGERIA
Abstract
The acute shortage of power generation in Nigeria often leads to a lot of temporally operational arrangement to avoid total system failure. However, this temporally measure to prevent system from collapsing further pose technical – economic crisis for both utility and stakeholders of power system operation. This paper is mainly focused on extensive assessment of 33 KV feeders’ reliability using various methods and causes of outages on the various feeders being studied. The cost implication of the outages to power producers and consumers using data collected from Power Holding Company of Nigeria (PHCN) were been calculated and analyzed and the result shown in table 2.4. The significant of this research is that it presents an approach that considered wide range of outage parameters (duration, load interruption, cause of outage frequency and customer population) as input to a complimenting collection of reliability assessments (Pareto analysis, frequency and duration method reliability analysis, distribution system reliability analysis and outage cost analysis) to obtain a variety of reliability information of the feeders being investigated.
3 |
Author(s):
DANBBATA, U.G., ABUBAKAR, Y.H..
Page No : 23-29
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MOBILE PHONE RADIATION COMPATIBILITY ISSUES AND HEALTH HAZARD
Abstract
Presently Nigeria is experiencing a steady growth in the telecommunication industry, with about twenty one (21) mobile wireless telecommunication service providers, about fifteen thousand (15,000) base transceiver stations (BTS) spread across the country, and above fifty million (50,000,000) lines (handsets) connected, (Nigeria Communication Commission,2010). There is growing concern among Nigerians about the possible health hazard of electromagnetic radiation from the BTS and the mobile handsets. This study focuses on measurement of electric field strength (v/m) radiated from the front end of the mobile handset during call session and from the mobile handset to the BTS. These measurements were carried out using electric field strength meter. Maximum electric field values were measured from the front side very close to the mobile phone for different phones and the results were compared with the compatibility standard provided by the International Commission on Non-Ionizing Radiation Protection, (ICNIRP, 1998) and a good agreement was obtained.
4 |
Author(s):
Yusuf, M, Salawu, H.
Page No : 30-39
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IMPEDANCE-SOURCE INVERTER DESIGN FOR UNINTERUPTED POWER (UPS) APPLICATIONS
Abstract
This paper presents design considerations of a Z-source inverter for a single-phase Uninterruptible power supply (UPS) system. The Z-source inverter system employs a unique LC network in the DC link. By controlling the shoot-through duty cycle, the Z-source can produce any desired output AC voltage, even greater than the battery voltage. The inverter has one switch less than the conventional two stage power conditioner, which leads to reduction of cost. The modulation pattern for the switches is described, and the design recommendations for the Z-source inverter are presented. The design of the inverter was verified by simulation.
5 |
Author(s):
Bichi, M. H..
Page No : 40-51
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ASSESSMENT OF CUSTOMER’S AFFORDABILITY AND WILLINGNESS-TO-PAY FOR WATER SUPPLY SERVICES IN DUTSE, NORTHERN NIGERIA
Abstract
This study was carried out in Dutse, to determine customers’ willingness to pay for water services, and whether they can afford the charges being proposed. The methodology adopted comprised of collection of relevant data; customer enumeration survey; sample surveys to determine customer’s willingness to pay for water service; and analysis of the data. The study found that customers are not satisfied with the level of water supply service but are willing to pay for improved service. Majority (57%) indicate willingness to pay between N750.00 to N1,500.00/month. Customers with monthly incomes of more than N20,000.00/month spend only 0.5% of their income on water service, whereas those with N10,000.00 – N20,000.00/month spend 0.33%, and those earning N5,000.00 – N10,000.00/month spend 0.67%. The study also found that whereas the cost of water in Dutse is $0.32/month ($1=N156) for single connection and $0.64/month for multiple house connections, the cost of water per m3 stands at $0.01/m3 for single connection and $0.02/m3 for multiple house connections. The major recommendations from the study include the development of a new tariff structure that would ensure improved services that matches the WHO standards with adequate cost recovery and sustainability.
6 |
Author(s):
Ayinla, A.I, Bichi, M.H, Jimoh, A.A..
Page No : 54-60
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INVESTIGATION OF BASE FLOW CONTRIBUTION INTO KADUNA RIVER
Abstract
Base flow and surface runoff are two important components that sustain a river or stream. Study was conducted at the Lower Kaduna river catchment, where Kaduna South Water Works was located in Kaduna to estimate the base flow discharge into the Kaduna River. The estimation was done using Local Minimum method of hydrograph separation from stream flow discharge data of thirty years (1977-2006). The total volume of base flow estimated within the period of study was 2.8240 x 1011 m3 representing 15.2% of total stream flow. The year 1984 with lowest stream flow within the reported period has highest base flow contribution with a total value of 9.382 x 109 m3 representing 34.2% of total stream flow for the year, indicating that the river was sustained through by the base flow. The lowest baseflow contribution occurred in 2002 with a value of 5.901 x 109 m3 (6.1%), while the stream flow was ranked first within the period under study. The result was grouped in ten years event, from 1977 to 1986 a sum of 1.084 x 1011 m3 base flow was estimated (19.45%), while from 1987 to 1996 and 1997 to 2006, 9.121 x 1010 m3 and 8.275 x 1010m3 were estimated representing 14.29% and 12.47% respectively. A downward trend in base flow was indicated while stream flow shows an upward trend from the statistical analysis. The research provides a frame of reference for the implementation of groundwater protection, uses, and management plans.
7 |
Author(s):
Attanda, M. L., Muhammad, A. I, Shema, A.
Page No : 61-69
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DEVELOPMENT AND PERFORMANCE EVALUATION OF A HAND-PUSHED WEEDER
Abstract
A hand-pushed mechanical weeder was developed and evaluated to determine its performance indices. The field performance was compared with traditional hand-held hoe on a variety of TZPB-SR maize crop grown field. The means of forward speed, actual field capacity and weeding efficiency are 0.092 m/s,0.028 ha/hr and 75.17% for the developed weeder as against 0.013 m/s, 0.0059 ha/hr and 77.98% for the manual hoe respectively. The mean effective operation time for the developed weeder on a 9 x10-4 ha field of a sandy loam soil at 14.85% moisture content was found to be 91 second with 164 number of weeds removed while that of traditional hoe was found to be 189 seconds with 153 number of weeds removed on the same size of field.
8 |
Author(s):
ABUBAKAR, M.S..
Page No : 70-82
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CONCEPTS, TECHNIQUES AND CONSTRAINTS OF PRECISION AGRICULTURE: AN OVERVIEW
Abstract
The growing food demands due to ever-rising human populations forced farmers to adopt resource-intensive and unsustainable practices that to improve economic returns and reduce environmental impact. Consequently, the concept of precision agriculture is rapidly spreading in developed countries as a tool face the challenging of agricultural sustainability. Many research works have been started in different parts of the world. Therefore, this paper discusses the overview of concepts, techniques and constraints of precision agriculture.
9 |
Author(s):
Amartey, Y. D, Sada, B. H, Hamidu, A. M.
Page No : 83-93
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THE USE OF PALM KERNEL SHELL ASH AS AN ADMIXTURE IN CEMENT MORTAR
Abstract
Palm kernel shell ash (PKSA) was used as admixture in cement mortar to determine the effect of PKSA on the properties of cement mortar. An experimental investigation was carried out to establish the trend of the properties changes with reference to the proportion of PKSA added. The ash was used at additional levels of 0.5 to 3.0% by weight of cement. Physical tests on cement were performed on cement/PKSA mixes. The consistency and setting times all increased with increase in the level of PKSA. Twenty-eight (28) days saturated compressive strength of the mortar cubes were in the range of 24.76 to 25.42MPa for replacement level 0.5 to 3.0%.while it gave a reading of 26.89MPa at no addition (0.0% PKSA). These results confirm that the combined use of cement and PKSA between 0.5 to 3.0% addition level) have no significant influence on the physical properties and on the compressive strength of cement mortar and could safely be used.