Evaluation of combined heat treatment techniques of testing hardness and tensile strength of mild carbon steel commonly used in Nigeria

This study investigated effect of combined heat treatment on the hardness and tensile strength of 0.25 - 0.35 grade of medium carbon steel. Heat treatment at 900 °C for four hours was done and six specimens of each were then quenched in water. Results showed that the hardness and tensile strength ranged from 113.7 to 184.4 HB and from 383.84 to 621.2 N/mm2, respectively, for hardening temperature from 700 to 950 °C; and were from 180.2 to 125.5 HB and 594.7 to 4143 N/mm2, respectively, when the steel was quenched from 900 °C for tempering temperatures from 250 to 600 °C. The result of tempering (from 250 to 600 °C) when previously quenched (from 850 °C) steel showed decreasing values of hardness (from 400 to 248 HB) and of tensile strength (from 1320 to 819 N/mm2). The microstructure of the normalized sample was observed to be finer and more homogenized than the one observed in the as-rolled condition of the sample. This invariably led to the higher hardness and tensile strength values recorded.Keywords: Hardness, Tensile strength, quenching, microstructure, ferrit

Prevalence of Cataract Blindness in Rural Ethiopia

Background: Over three-quarter of all blindness worldwide are preventable and usually caused by cataract and trachoma.Objective: To assess the prevalence of cataract blindness in rural Ethiopia in order to facilitate further health care planning.Methods: A Cross-sectional, community-based study of inhabitants over 40 years of age from villages in the Abeshge and Kebena Districts, south of Addis Ababa. A total of 1100 eligible participants were identified in the study. Visual acuity (VA) was measured using a Snellen’s E chart at 6 metres and eye examinations were performed using torch light, 2.5 X magnifying glasses and an ophthalmoscope. Cataract was defined as lens opacity identified as the cause of blindness and low vision after ruling out other causes. Unfortunately, there was no access to a refraction set and slit lamp to conduct thorough examinations.Results: The adjusted prevalence of bilateral cataract blindness (VA<3/60) was 2.4%, 95% confidence interval [CI], 1.8%–3.0%. Cataract is the major cause of bilateral blindness (66.7%) among the participants. The cataract surgical coverage was 28.9% for men and 18.1% for women. The adjusted prevalence of bilateral cataract and VA<6/60 was 3.6% (95% CI, 1.4%–5.8%). In this last group, the surgical coverage was 41.2% (persons) and 38.5% (eyes). Of all operated eyes, 30% could not see at 6/60. Inability to afford the procedure (64.5%) and poor knowledge of cataract (29.8%) were the reasons why surgery had not been performed.Conclusions: Cataract blindness is a major health problem in the study area with low surgical uptake. There is backlog of cataract blindness in the study area that will increase with ageing. This backlog was also reflected in other developing countries. Awareness campaigns, reducing cost, and expansion of surgical services may help to increase the cataract surgical rate, and women should be offered more cataract surgery. These results will enable health managers to plan effective interventions in line with Vision 2020. [Ethiop. J. Health Dev. 2011;25(2):156-160

Spatial Profit Differential of Yam Marketing in Gombe Metropolis, Gombe State, Nigeria.

The study examines the spatial profit differentials of yam marketing in Gombe metropolis. Primary data were collected using questionnaires which were administered to 40 randomly selected respondents, 10 from each selected markets. Farm budget model was used to analyse the data. The result indicated that 60% of the respondents were within the age bracket of 21 to 40 years and the literacy level of the respondents was moderate, where those with primary and secondary education constituted 25% each  out of the total respondent. The highest profit was realised in Pantami market with N19.2/tube and the lowest was in Gombe Old market with N32.5/tube. The major constraints to yam marketing were insufficient capital with 32.5 percent while high cost of transportation and poor storage facilities constituted 25% each. It was therefore recommended that appropriate means of products  preservation and famers should form associations in order to  have access to loans which  would boast yam marketing. Keywords: Spatial, Differential, Marketing, Ya

Analysis of cost efficiency in food crop production among small-scale farmers in Adamawa state, Nigeria

Efficient allocation of resources has been a problem in small holder farm economy in Nigeria. The study analyzes cost efficiency in food crop production among small-scale farmers in Adamawa State, Nigeria. Specifically, the socioeconomic characteristics of food crop farmers in the study area were described, their various cropping systems identified and the cost efficiency indices of the farmers determined. Data were collected from 360 randomly selected food crop farmers in eight local government areas spread across the four ADP zones of the State using structured questionnaires. The analytical tools were descriptive statistics involving the use of frequency tables and inferential statistics involving the use of stochastic frontier cost function. The result revealed that married female farmers constituted majority (57.22%) of the respondents. Their literacy level was high, as 84% of them had some form of formal education. The respondents cultivated an average of about two hectares of farm land using personal savings. Eleven cropping systems were identified with mixed cropping accounting for about 53% of the cropping systems and about 54% of the total hectarage allocations. The maximum likelihood estimates of the stochastic cost function revealed that the explanatory variables; extension contact, crop diversification and credit availability were significantly and positively related to cost efficiency in the study area. The cost efficiency index ranged from 0.18-0.98, with a mean of 0.84 implying that an average farm in the study area has the scope for increasing cost efficiency by 16% given the existing technology. The study recommended farmers education on fundamental farm management skills to enable farmers plan, evaluate and appraise their farm business activities among others.KEYWORDS: Cost efficiency, Cropping systems, Small-scale food crop farmers, Adamawa State, Nigeri

A Study of Extracranial Aneurysms at UNTH in Enugu, Nigeria

Previous studies on aneurysms in Nigeria have either been case reports or studies of peripheral aneurysms. No study has comprehensively evaluated all aspects of this disease as an entity among Nigerians. The need therefore arises to re-evaluate this lesion so as to make deductions on incidence, sex ratio, aetiology and management. This is a retrospective descriptive study of arterial aneurysms at the University of Nigeria Teaching Hospital (UNTH), Enugu. Those treated between January 1993 and December 2002 were included for the study. Datawere obtained frommedical records for all patients admittedwith aneurysms over the study period. Atotal of 26 patientswere admitted during the period, but 24 case noteswere analysed. The age rangewas 10-75 yearswithmale: female ratio of 1.4:1. Traumatic pseudo aneurysms accounted for 16 cases (67.0%)while true aneurysms comprised the remaining.Of all the aneurysms, femoral artery with most of the pseudo aneurysms had 8 out of 24 (33.0%).This is followed by the infra-renal abdominal aorta (5/24, 21.0%) and other sites (11/24, 46.0%). Diagnoses were made clinically in most cases and by abdominal ultrasonography in abdominal aortic aneurysms. Twenty-one patients had surgical interventionwith 9.5% operativemortality. The incidence of aneurysm is low in our locality (2.6/year) based on the rate of diagnosis.Abdominal aorta harbours most of the true aneurysms with diameter ranging from 8.0-15.0cm without rupture. Untreated, all will eventually rupture with catastrophic consequences. Treatment involved excision with graft interposition. This is not only expensive but the graft is often not readily available. As a solution, grafts should be stocked with drug revolving fund.Keywords: trauma, true and pseudo aneurys

A Mathematical Model For Attenuating the Spread Of Diabetes and Its Management In A Population

We study the dynamics of diabetes in a population based on the etiology of the disease. In carrying out the study, we proposed that; a population generate non-diabetic non – susceptible sub-population, and a non-diabetic susceptible sub-population, the non-diabetic susceptible sub-population can further generate a population of diabetics without complication, who can later transit to a population with diabetic complications. Based on the etiology dynamics, we proposed control measures at the point of transition from the population to non-diabetic susceptible population, and at the point of transition from diabetes without complications to diabetes with complications. For this study, we intend to look at the control measure. In this regard, we proposed a mathematical model for the dynamics of diabetes by incorporating a control parameter h, so as to investigate how to control diabetes in a population. The result of the study suggested that; we need to control the incidence of diabetes, I(t), and improve the control measure, h, for transition from diabetes without complication to diabetes with complication. Thus entailing going  further in research to; Look into the dynamics of the genetics of transmission of the diabetic gene, to investigate how to reduce the spread (and hence the incidence I(t)) of diabetes, and to also look into the influence of the control factor h, on the dynamics of glucose metabolism, this will give an insight on how to manage diabetic patients.Keywords: Diabetes, Population, Genes, Genetics, Etiology

Linear Subspaces of Solutions Applied to Hirota Bilinear Equations

- Linear subspace of solution is applied to Boussinesq and Kadomtseve-Petviashvili (KP) equations using Hirota bilinear transformation. A sufficient and necessary condition for the existence of linear subspaces of exponential travelling wave solutions to Hirota bilinear equations is applied to show that multivariate polynomials whose zeros form a vector space can generate the desire Hirota bilinear equations with given linear subspaces of solutions and formulate such multivariate polynomials by using multivariate polynomials which have one and only one zero

Estimating the shear strength of sisal fibre reinforced concrete

This research examines the shear strength of Sisal Fibre Reinforced Concrete (SSFRC).Sisal Fibre (SSF) addition was at 1% by weight of dry constituents, this is considered the upper limit for workable mixes in the absence of water reducing agents. Beams of various grades of concrete (20N/mm2 to 40N/mm2 ) were tested and they all failed in shear. Experimental results of beams were compared with modified versions of the BS 8110 formula for shear strength in concrete, to determine the best fit. The inclusion of SSF at 1% addition increased the compressive strength of the concrete mix by an average of 16.9% and the shear strength by 16%. However, the shear strengths of the SFRC are only greater than those of normal concrete of corresponding compressive strengths by 9.5%. The equation proposed may be used to estimate the shear strength of SSF reinforced concrete at this level of fibre addition.Keywords: Compressive strength, Reinforced concrete, Shear strength, Sisal fibre

Effect of Variety, Seed Rate and Row Spacing on the Growth and Yield of Rice in Bauchi, Nigeria

Field experiments were conducted at Abubakar Tafawa Balewa University, Fadama Farm Bauchi, during the rainy seasons of 2006 and 2007 to study the effects of variety, seeding rate and row spacing on growth and yield of rice. Two varieties of rice; Ex – China (Indigenous and upland/lowland) and NERICA-1 (improved and upland), three seeding rates (32, 54 and 75 kg/ha) and four row spacings (15, 20, 25 and broadcast) were used during the study. The treatments were combined and laid in a split – split plot design with three replications. Variety was placed in the main plot, seeding rate in the sub plot while row spacing was placed in sub –sub plot. Data were collected on parameters such as plant height, number of tillers per plant, spikes per hill, spikelets per spike and number of seeds per spike, seed weight per hill, 1000 grain weight and yield kg ha-1 and analyzed using analysis of variance procedure for split – split plot and significant differences among the treatment means were separated using the Duncan multiple range test (DMRT). Variety Ex-China produced significantly (P<0.05) higher numbers of tillers per plant and spikes per hill. However, NERICA-1 produced significantly (P<0.05) higher numbers of spikelets per spike, seeds per spike, weight of seed per spike, weight of seed per hill, 1000 grain weight and yield in kg ha-1 than Ex-China. Row spacings of 15, 20 and 25cm also had significant effects on the number of tillers per plant, number of spikes per hill, number of spikelets per spike, number of seeds per spike, weight of seed per spike, weight of seed per hill, 1000 grain weight and yield kg ha-1 over the control. From the factors studied, seeding rate did not show any significant difference during the two years of investigation. Interactions were also observed among the factors studied. Therefore, row spacings irrespective of the method used, or hole planting of rice could be more appropriate for optimum grain yield.Key words: Seed rate, Row spacing, Spike

Nigella sativa (black seed) extract improves spatial learning abilityin albino mice

This study was carried out to assess the memory enhancing effect of Nigella sativa Extract on mice using Morris Water Maze. The study was conducted on 30 Albino mice of both sexes randomly divided into 5 groups with 6 animals each. Group 1 served as control and was treated with oral distilled water, Groups 2, 3 and 4 were treated orally with 1ml/kg, 2ml/kg and 4ml/kg body weight of the Nigella sativa Extract (NSE) respectively for 3 days, and Group 5 was treated with 100mg/kg body weight memory enhancing drug-Piracetam. Latency to locate the platform and the frequency of crossing the platform was measured. The result showed a decrease though not significant in latency to locate platform between training days 1 and 2 in 2ml& 4ml Nigella sativa groups (49.92±10.75 NSE 1 ml/kg; 29.63±7.12 NSE 2ml/kg; and 34.04±6.51 NSE 4ml/kg), also when compared to control and Piracetam groups, with the Piracitam group having a similar latency to control. The increase in there frequencies of platform crossing compared to control was significant at p=0.045 and was dose dependent (1.67±0.72 1ml/kg NSE; 1.83±1.60 2ml/kg NSE; 3.50±0.76 4ml/kg NSE; and 4.17±0.87 100 mg/kg Piracetam). These findings conclude that acute administration of Nigella sativa has a beneficial effect on learning and memory and has a better effect on learning but not memory than piracetam.Keywords: Nigella sativa, learning, memory, Morris water maz