Fractal Characterization of Dynamic Systems Sectional Images

Image characterizations play vital roles in several disciplines of human endeavour and engineering education applications in particular. It can provide pre-failure warning for engineering systems; predict complex diffusion or seeping of radioactive substances and early detection of defective human body tissues among others. It is therefore the object of this study to simulate three selected known surfaces that are of engineering interest, pass section plane through these surfaces arbitrarily and use fractal disk dimension to characterize the resulting image on the sectioned plane. Three carefully selected surfaces based on their engineering education and application worth’s were simulated with respective relevant set of equations. In each case studied, the simulation was driven either by random number generation with seed value of 9876 coupled with relevant set of equations or by numerical integration based on Runge-Kutta fourth order algorithms or combination of both. However, all simulations were coded in FORTRAN 90 Language. Section plane was passed through each simulated surface arbitrarily and in two hundred (200) different times for the purpose of obtaining reliable results only. Image obtained at less or equal to four percent (4%) tolerance level by sectioning was characterised by optimum disks counting algorithms implemented over ten (10) scales of observations and five (5) different iteration each. The estimated disk dimension was obtained by implementing the least square regression procedures on optimum disks counted at corresponding scales of observations. A visual and fractal disk dimension characterization of selected images on sectioned plane form cases studied validated algorithms coded in FORTRAN 90 computer language. The surface of Case-III is the most rough with disk dimension of 2.032 and 1.6% relative error above the dimension of smooth surface (2.0). This is followed by Case-II with disk dimension of 1.905 and 4.8% relative error below the dimension of smooth surface. Case-I has the least disk dimension of 1.897 and with 5.2% relative error below smooth surface. Case-I and case-II that suffered negative relative error originated from set of linear systems while Case-III that suffered positive relative error originated from set of non linear systems. Non linearity manifested in graphical display of disk distribution by frequency in Case-III by multiple peaks and substantial shift above disk dimension of 1.0.This study has demonstrated the high potentiality of fractal disk dimension as characterising tool for images. The coded algorithms can serve well as instruction material for students of linear and non linear dynamic systems. Keywords: Fractal, Sectional Images, Fractal Disk Dimension, Dynamic Systems and Algorithm

Community survey of childhood injuries in North-Central Nigeria

Background and purpose: Childhood injury is of great significance globally and epidemiological data on the subject in most developing countries are inadequate. Informed demographics can help direct resources toward research and programs most likely to reduce the burden.Methods: A survey to determine the prevalence, mechanism of injury, and intervention measures was conducted using pretested questionnaires distributed to consented parents/guardians of children 15 years and younger who presented at six selected hospitals (representing public and private and low or high income clientele hospitals) for healthcare needs for any reason. Results were analyzed using Epi Info (6.04) and SPSS software (version 15).Results: There were 1088 respondents comprising parents (96.5%) and guardians (3.5%). Most were 21–40 years old (86.2%) and 51.9% of them had more than three children living with them. Over 50% had witnessed injuries of their wards within the previous 12 months and about a quarter admitted that a child was injured more than once. The risk of injury was twice in the male child mainly in the 1–4 years age group. Most injuries (65.2%) occurred at home, with 98% being unintentional from falls (62.6%) and 71.9% of the times the parents witnessed the injury as it occurred. The intentional injuries (2%) followed assaults during fights among peers. Treatment was provided at home in  58.5% of children by the parents, whereas only 27.5% took their wards to the hospital; 12.6% received treatment at patent medicine stores and 1.3% from the herbal/ traditional bone setters’ home. Two deaths resulted from the injuries from fall, whereas six children had residual deformity as a result of home injury. Three-quarter (74.8%) of the respondents believed childhood injuries were preventable.Conclusion: Childhood injuries are not uncommon in the community. The significant proportions of respondents using inappropriate means of treatment and who believed that injuries are not preventable represent targets for health education and counseling in the community.Keywords: childhood injury, epidemiology, injury education, preventio

Energy Analysis of Jebba Hydropower Plant

Jebba hydro power station is one of the largest singularly installed electricity generation plants in Nigeria with generating capacity of 540-560 MW. n this work, energy efficiency of the power generating and transmitting plant (Jebba) was analyzed. The analysis was carried out using efficiency of supply, seasonal variation of hydro dam as well as technical losses in the process of transmission. Results of the study showed that power generating units numbers 1 and 5 (2G1 and 2G5 respectively) have the highest amount of energy generated throughout the period under consideration (2006-2011). The units generated total energy of 3,471,931 MWh and 2,976,845 MWh respectively, while 2G6 unit generated low amount of 1,163,516 MWh. On a general note, the total energy generation in the six production units was found to behave as: 2G6<2G4<2G2<2G3<2G5<2G1 for the period under consideration. Thus, 2G6 was found to be the most unreliable generating unit when compared to the remaining five units. Low plant availability of 2G6 unit, the unstable grid system and seasonal variation of water were identified as the key factors responsible for the reduction in the efficiency of the power plant. Based on the available data (the estimated efficiency of supply and production, overall efficiency of the plant and the seasonal variation in energy generated) over the period under consideration, the energy generation pattern of the hydropower station is relatively stable and the energy generation operations is efficient (averaged 97%). This study concludes that if the highlighted technical challenges are given due attention, in the years ahead, the plant operating efficiency will be in upward direction above 97 %. Keywords: Hydropower, plant, transmission, energy, efficiency, da