357 research outputs found
Physio-Chemical and Mechanical Behaviour of(Pinussylvestris) as Binders on Foundry Core Strength
The mechanical potential of sand core binders made withPinussylvestris has been examined. Ota silica
base sand bonded with 6% of cassava starch in admixed proportion of Pinussylvestris was tested for
tensile, compressive strength and permeability to establish the binding efficiency. Tensile strength of the
green baked core were oven baked at 50°C, 100°C, 150°C and 200°C.The cylindrically shaped
permeability specimens were tested with permeability meter. Study revealed thatPinussylvestris showed
an improve properties at 6% cassava starch at 200°C
Influence of Plating Parameter and Surface Morphology on Mild Steel
The plating parameter effect of zinc deposition on mild steel substrates was investigated. The results
showed an improved surface finished and homogeneous layer. The distance between the anode and the
cathode on voltage, plating time and coating thickness were considered. The mild steel was deposited
into solution of zinc bath for varying voltage between 0.5 v and 1.0v. It was discovered that the sample
plated at 0.8v for 15 minutes gives the best plating deposition and appearance. The surface
morphology of the plated sample was analyzed by Focused ion beam scanning electron microscopy
(FIB-SEM), AFM and X-ray diffraction
COMPARISON OF ROAD TRAFFIC ACCIDENT PREDICTION MODELS FOR TWO-LANE HIGHWAY INTEGRATING TRAFFIC AND PAVEMENT CONDITION PARAMETERS
In Nigeria, literature on the integration of traffic of pavement condition and traffic characteristics in predicting road traffic accident frequency on 2-lane highways are scanty, hence this article to fill the gap. A comparison of road traffic accident frequency prediction models on IIesha-Akure-Owo road based on the data observed between 2012 and 2014 is presented. Negative Binomial (NB), Ordered Logistic (OL) and Zero Inflated Negative Binomial (ZINB) models were used to model the frequency of road traffic accident occurrence using road traffic accident data from the Federal Road Safety Commission (FRSC) and pavement conditions parameters from pavement evaluation unit of the Federal Ministry of Works, Kaduna. The explanatory variables were: annual average daily traffic (aadt), shoulder factor (sf), rut depth (rd), pavement condition index (pci), and international roughness index (iri). The explanatory variables that were statistically significant for the three models are aadt, sf and iri with the estimated coefficients having the expected signs. The number of road traffic accident on the road increases with the traffic volume and the international roughness index while it decreases with shoulder factor. The systematic variation explained by the models amounts to 87.7, 78.1 and 74.4% for NB, ZINB and OL respectively. The research findings suggest the accident prediction models that should be integrated into pavement rehabilitation.
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Democratic Consolidation in Africa: The Ghanaian Paradigm
The ‘Third Wave\u27of democracy resulted in transition galore in Africa. Authoritarian governments abandoned authoritarianism fora reconstructed political society which mirrors the institutions and processes of liberal democracy. What is strange however, is the fact that most of the countries that transited to democratic rule in the region about three decades ago are not making significant progress towards consolidating their hard earned democracy. Electoral violence and some other anti-democratic practices have made the mantra of good governance a mere rhetoric, and kept democracy perpetually nascent in most of the countries in the region. But worthy of note is the reference being made to Ghana, by some observers of African politics, as a beacon of democracy in Africa. The crux of this paper therefore is to attempt a critical evaluation of Ghanaian\u27s democratic experience to determine the extent to which the country can be referred to as a consolidated democracy. Descriptive/qualitative method was used for data analysis. The paper discovered that Ghana indeed possesses some strikingly unique democratic experience which distinguish it from other African states. Although the countryis still struggling with some anti-democratic challenges like vote buying and executive recklessness, which if not properly addressed may erode any democratic gains recorded so far. Nevertheless, the impressive democratic credentials or the indices of democratic consolidation in the country as discovered by this research, can make one to conclude that Ghana is on the path of achieving democratic consolidation
Doe productivity indices and sire effects of a heterogeneous rabbit population in South-western Nigeria
Doe productivity indices are important in evaluating rabbit population since it influences the efficiency and profitability of rabbit production for small-holders and commercial rabbit production. Rabbits for this study were obtained from heterogeneous populations reared in south-western Nigeria, and a total of fifty-six adult rabbits (6 months old) comprising of 49 does and 7 sires were randomly allocated into sire families. Reproductive data were taken from each breeding doe and recorded for each sire family. The reproductive data obtained include annual productivity indices for each doe and sire family at birth, weaning and at week 12 post-partum. The total number of kits delivered at each kindling were recorded as the litter size at birth , the numbers weaned/doe/year were derived by multiplying the average litter size at weaning by number of litters/doe/year. The numbers of fryers/doe/year were obtained by multiplying average number weaned/doe by number of litters/doe/year multiplied by post weaning survival. Annual fryer yield (kg)/doe/year were obtained by multiplying total number of fryers/doe/year with live market weight (kg). Kilogram meat/doe/year were derived from the product of annual fryer yield (kg)/doe/year and the dressing percentage (0.55). Descriptive and inferential statistics were computed using SAS® 2004. Results showed that, the long kindling interval (93 to 115 days ) between two consecutive litters affected overall numerical doe productivity with a range of 6 to 27, 3 to 21 and 3 to 18 kits per doe/year at kindling, weaning and 12th week of age respectively. Annual fryer yield/doe/year was 20.24 Kg and the projected Kg meat/doe/year was 11.13 Kg. Mortality was highest in the first two weeks of life and continued to occur throughout the period of the study though at varying degrees across sire families. There was significant sire effect (P<0.05) in litter size at weaning and kindling- interval in the sire families. It was concluded that, the major factors affecting doe productivity indices in this population were low litter size at birth, long kindling interval and pre-weaning mortality. Thus, future genetic improvement programmes targeted towards productivity for this rabbit population must consider selection for traits which include increased litter size at birth, short kindling interval and low pre-weaning mortality in the maternal lines while litter size at weaning and kindling interval must be considered for the paternal lines
EVALUATION OF INFESTATION AND DAMAGE BY THE LARGER GRAIN BORER (PROSTEPHANUS TRUNCATUS) (HORN) (COLEOPTERA: BOSTRICHIDAE) ON SELECTED FOOD GRAIN CROPS
The study evaluated the ability of the larger grain borer (LGB), Prostephanus truncatus (Horn) to infest and damage two varieties of sorghum (Sorghum bicolour), Sesame (Sesamum indicum) Cowpea (Vigna unguiculata) and maize (Zea mays). 100 g each of the grain products were infested with 5 pairs (5 males and 5 females) of 1-10 day old LGB for 90 days. At 90 days post-infestation of the crops, the insects and grain dust generated by the feeding activities of the insects were sieved out of the grains; the grains were separated into damaged and undamaged and data were taken on number of adult P. truncatus, number of larvae and pupae, number of larvae and pupae, number of adult mortality, weight of dust (g), weight of damaged grains (g), weight of undamaged grains (g) and final weight of grains (g). The results showed that all the 5 pairs of adult LGB introduced into the cowpea and sesame varieties died. Likewise, neither larvae nor pupae were found in the two grain products. The highest mean number of larvae and pupae (18.5) was recorded in the Suwan-1 maize variety, and it was significantly (P < 0.05) higher than the mean number found in the other grain products studied. The mean number of larvae (7.25) in Solo maize variety was significantly (P < 0.05) higher than the mean larvae number of 4.25 and 2.50 in Eyinfun and Ex- Minna sorghum varieties respectively. Significantly (P < 0.05) higher percentage grain damage (49.76) and percentage weight loss (12.89) were recorded in the Solo maize variety compared to percentage grain damage and percentage weight loss in other grain products. Likewise, the grain damage (23.06 %) and weight loss (8.04 %) in the Ex-Minna sorghum variety were significantly  < 0.05) higher than percentage grain damage and percentage weight loss obtained in other grain products except Solo maize. A significantly (P < 0.05) lower grain damage (1.35 %) and grain weight loss (1.43 %) were obtained in the NICRIBEN and E8 sesame varieties respectively. The result of this study indicates the ability of LGB to bore and damage sorghum, maize, sesame and cowpea; with breeding restricted only to maize and sorghum. There were varietal differences in response of the grain products to LGB infestation and damage. Considering the importance of sorghum, maize, sesame and cowpea as a cheap source of carbohydrate and protein; concerted effort should be geared at controlling infestation of the grain products by LGB
Automating consumer's connections to the distribution network for enhanced performance
Abstract:Trial and error approach which involves service interruption is usually carried out to resolve unbalance on phases in power distribution system. This approach might improve the phase voltage and current but the resultant effect (change) does not last for too long; thereby reduces the market value in terms of quality and reliability of supply. To enhance the performance of the secondary distribution system there is a need for an automating technology. The aim of this paper is to introduce a method and technology developed for resolving imbalances in a secondary distribution system as a result of the uneven distribution of single phase load across a three phase power system. The technology developed is able to monitor, acquire/display collected data and perform self changing switching actions electronically. This action is in form of rearrangement or transfer of consumer loads for optimal performance of the distribution feeder. The proposed switching technology is based on open- transition switch that enables transfer or rearrangement of consumer loads in a three-phase system within milliseconds with supervisory control system. The following methodologies: System Simulator - Matlab (Simulink), Virtual Instrumentation-Lab VIEW and Hardware implementation were applied for the validation of the proposed techniqu
Synergetic performance of palm oil (Elaeis guineensis) and pine oil (Pinus sylvestris) as binders on foundry core strength
Possibilities of foundry sand core binders made with combination of Elaeis guineensis and Pinus sylvestris have been evaluated and the combine effect of these oils as binder were discussed. Core specimens made with Ota silica base sand bonded with 6% of cassava starch in admixed proportion of E. guineensis and P. sylvestris were tested for tensile, compressive strength and permeability to establish the binding efficiency. Tensile strength of the green baked core were oven baked at 50, 100, 150 and 200°C; cooled to room temperature and tested with universal strength machine. The cylindrically shaped permeability specimens were tested with permeability meter. The combine synergetic performance of the oil with Manihot esculenta crantz at 3 and 6% respectively show an improved tensile strength of about 90% above the P. sylvestris admixed. A compressive strength (CS) with baking temperatures up to 1150 KN/m2 was achieved at 6% starch with 2% (palm and pine oil) and 3% H2O and increased up to 1350 KN/m2 at 6% starch with 6% (palm and pine oil) and 3% H2O. Cores made with composites of 6% starch, 6% palm and pine oil and 3% water and 6% starch, 6% palm oil and 3% water will be suitable for intricate copper, aluminium, iron and steel casting
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