845 research outputs found

    Integrated atomistic process and device simulation of decananometre MOSFETs

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    In this paper we present a methodology for the integrated atomistic process and device simulation of decananometre MOSFETs. The atomistic process simulations were carried out using the kinetic Monte Carlo process simulator DADOS, which is now integrated into the Synopsys 3D process and device simulation suite Taurus. The device simulations were performed using the Glasgow 3D statistical atomistic simulator, which incorporates density gradient quantum corrections. The overall methodology is illustrated in the atomistic process and device simulation of a well behaved 35 nm physical gate length MOSFET reported by Toshiba

    Factors associated with seizure severity among children with epilepsy in Northern Nigeria

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    Objective: To describe how seizure severity in children with epilepsy may be affected by certain socio-demographic and clinical variablesDesign: A cross-sectional studySetting: At the Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, NigeriaParticipants: Sixty children and adolescents who were being followed up for seizure disorder at the child neurology clinicIntervention: Information on socio-demographic characteristics was obtained with a questionnaire, details of neuro-logical co-morbidities were extracted from the participants’ records, and seizure severity was assessed with the Na-tional Hospital Seizure Severity Score 3 tool.Main Outcome Measure: Chi-square test was used to establish the relationship between categorical variables, while the Independent t-test was used in describing the differences between means. Simple linear regression was calculated to assess the predictability of seizure severity.Result: The median age was ten years (IQR = 6-13 years), with a male dominance (1.5:1). The Seizure Severity Score (SSS) ranged between 3 and 24 units, with a mean of 12.22 ± 4.29 units. The only characteristic that had a significant association with SSS on bivariate analysis was the “presence of co-morbidities” (p=0.019). A simple linear regression revealed that the presence of a neurological co-morbidity predicted an increase in the SSS by 2.67 units. [R2 = 0.091, F (1, 58)= 5.837, p = 0.019. ꞵ = 2.67, t= 2.42, p= 0.019.]Conclusion: This study shows that neurological co-morbidities predict worsening seizure severity. This knowledge may influence prognostication and the charting of a treatment trajectory

    Implications of Micro-Level Fractal Poverty Traps on Poverty Reduction Strategies at Meso and Macro Levels

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    Poverty, particularly in developing countries, is endemic and has attained a crisis stage. It is compounded by conflicts, corrupt/inefficient governments and other manmade issues that seem to keep people in perpetual deprivation and want. Although serious, this poverty trap is fixable. This paper reports on an ongoing research about poverty reduction strategies. It is based on the proposition that the first step in poverty reduction is understanding what makes an agent trapped. Therefore, this paper conceptualises poverty traps as fractal, self-perpetuating conditions when individuals are caught in a vicious cycle of poverty and continue to suffer from undesirable hardships for a long period of time. Using the neo-classical economic development theory and data obtained from the United Nations Development Programme, this paper argues that current poverty reduction strategies, which have been in use over the last five decades, have been ineffective. From the experiences of one of the authors in poverty reduction over the last two decades, a new poverty reduction strategy that focuses on individuals is thus proposed. This strategy uses the synergetic concept that indicates the simultaneous causation of poverty through the interaction between the individual and the context. This paper demonstrates that individuals in poverty are caught between externalisation and internalisation of conditions that are nonetheless transient and removable. Based on this new understanding, a four-stage interactive model called Learn, Relate and Adapt (LERA) is proposed for use in poverty research and the poverty reduction implementation strategy. Keywords/Phrases: poverty, fractal poverty, neo-classical economic development model, synergetics, LERA Mode

    Economics Analysis on the Development of Nigerian Offshore Marginal Fields Using Probabilistic Approach

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    Marginal Field Development in the prolific Niger Delta environment is of strategic importance to the Federal Government of Nigeria’s drive towards aggressive Reserve and Production Capacity enhancement. The objective of this study is to provide a perspective on portfolio diversification, investment and resource development on offshore marginal field in Nigeria. The economic analysis was carried out deterministically using economic indices like Net Present Value, Internal Rate of Return, Present Value Rate and others. Probabilistic model was also incorporated to assess the impact of the uncertainties in the input parameters using Monte Carlo simulation through the use of Crystal ball software. The key uncertainties were represented and their respective impacts on economic viability defined. The deterministic model results obtained from the studies were very impressive with Net Present Value of $526,749,924.84 at a discount value of 15% and Internal Rate of Return at 60%. Probabilistically, certainty of having a positive net present value (NPV) and good internal rate of return (IRR) values far above the hurdle rate for investment in Nigeria was obtained. The sensitivity analysis outlined oil price and tax rate as key sensitive parameters in maximizing profit. These clearly showed that the development of offshore marginal fields in Niger Delta of Nigeria is economically viable. Key words: Offshore marginal field; Probabilistic approach; Sensitivity analysis; Economic yardstic

    Investigating the cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels

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    The effect of cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels was investigated. Samples of high carbon steel were spheroidized annealed and then machined prior to the hardening process. Molasses solution of viscosity equals to that of engine oil was prepared by adding water. The samples were normalized and then austenitised at 800oC and soaked for 40 minutes and then quenched in water, engine oil, raw molasses and the prepared molasses solution. Cooling rate curves of all the quenching media used were developed. The highest cooling rate of 60oC/s was attained by the prepared molasses solution. Hardness of the test samples was evaluated. The test results obtained show that the highest hardness value (525 HVN) was obtained from the sample quenched in the prepared molasses solution. Microstructures of the various samples were analyzed using OM and SEM. In all the tests samples martensite structure was observed. It was observed that the prepared molasses solution has higher severity of quenching than that of engine oil but lower than that of water. The research showed that cane molasses can harden high carbon steel without cracking the component in the same way as engine oil, hence, molasses could be a very good alternative to engine oil for use as quenching medium

    The effect of “Gadagi” tea on liver function and serum glucose concentration in albino rats

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    Effect of oral administration of “Gadagi” tea on liver function and serum glucose concentration was assessed on thirty (30) healthy non – pregnant female albino rats. The animals were grouped and administered different doses (mg/kg) i.e. (low dose; 0.75mg/kg for “Sak,” 1.40mg/kg for “Sada” and 2.10mg/kg for “magani.” Standard dose; 1.50mg/kg for “Sak,” 2.80mg/kg for “Sada” and 4.20mg/kg for “magani.” High dose; 3.00mg/kg for “Sak,” 5.60mg/kg for “Sada” and 8.30mg/kg for “magani”) for a period of one week. Animals that were not administered the tea constituted the control group. At the end of one week, the animals were sacrificed and their serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), bilirubin (total and direct) and glucose levels were determined. Mean serum glucose level of the control animals was significantly higher (

    Effects of time of meat purchase on the level of microbial contamination of beef from retail points in Samaru market, Zaria-Nigeria

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    The meat retail selling points are the major places where people usually purchase meat from morning through to evening at retail points in Samaru, Zaria. A total of 100 meat samples were collected from five different retail meat selling points in Samaru market Zaria, Kaduna state. Twenty samples were obtained from each retail point (10 samples in the morning and 10 in the evening). The meat samples were tested for total aerobic and coliform plate counts to determine the effect of time on the level of microbial contamination. The result of the study shows that there was a statistically significant difference (P<0.05) between the aerobic plate counts of samples obtained in the morning and those of samples obtained in the evening. Similarly, there was a statistically significant difference (P<0.05) between the total coliform counts of the morning and evening samples. This suggests that there were increases in both total aerobic and coliform plates counts from the morning samples compared to evening samples. The minimum aerobic plate counts (6.0 log10 CFU/g) obtained exceeded the permissible value of (5.7log10 CFU/g) while minimum coliform counts (4.7 log10 CFU/g) exceeded the permissible value of (2.7 log10 CFU/g). This is of serious public health concern. It was concluded that there were increases in level of total aerobic and coliform counts in the meat samples obtained in the evening compared to those obtained in the morning and the minimum counts of both aerobic and coliform counts in morning and evening samples exceeded the minimum acceptable level in all the five retail points. The study demonstrated that it is better to purchase meat from retail points in the morning than evening because of the observed increase in microbial loads in the evening samples which increases the chances of meat-borne infection to consumers.Keywords: Aerobic, coliform counts, meat, retail points

    Investigation of Cu/TiO₂ synthesis methods and conditions for CO₂ photocatalytic reduction via conversion of bicarbonate/carbonate to formate

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    This work is aimed at improving the photocatalytic activity of TiO2 in the reduction of CO2. TiO2 and Cu/TiO2 at 5 wt% copper bulk loading were synthesised using the sol-gel method at a pH of 0.4 and 1.5. The synthesised pure TiO2 samples, alongside the commercial TiO2 (Degussa® P25), were also doped with copper via the incipient wetness method. The low pH and the presence of copper inhibited the anatase-rutile transformation. Copper existed in Cu(I) and Cu(II) states in all the doped samples, with the Cu(I) to Cu(II) ratio intimately linked with the anatase to rutile ratio. The UPS data have shown the type II band offset between TiO2 and CuO. The performance of the samples prepared was tested through the reduction of sodium bicarbonate-carbonate buffered at pH > 8. Commercial TiO2 impregnated with Cu demonstrated the highest formate production rate of 173 µmol·g−1·h−1 at pH 11. This study demonstrated the synergetic effect of the anatase-rutile mixture of phases, the reaction pH, and the copper dopant in improving the photocatalytic activity of TiO2

    Solutions of Chi-square Quantile Differential Equation

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    The quantile function of probability distributions is often sought after because of their usefulness. The quantile function of some distributions cannot be easily obtained by inversion method and approximation is the only alternative way. Several ways of quantile approximation are available, of which quantile mechanics is one of such approach. This paper is focused on the use of quantile mechanics approach to obtain the quantile ordinary differential equation of the Chi-square distribution since the quantile function of the distribution does not have close form representations except at degrees of freedom equals to two. Power series, Adomian decomposition method (ADM) and differential transform method (DTM) was used to find the solution of the nonlinear Chi-square quantile differential equation at degrees of freedom equals to two. The approximate solutions converge to the closed (exact) solution. Furthermore, power series method was used to obtain the solutions for other degrees of freedom and series expansion was obtained for large degrees of freedom
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