DEVELOPED PROBABILISTIC REDUCTION FACTORS FOR LOPHIRA ALATA (EKKI) TIMBER JOISTS SUBJECTED TO CREEP-RUPTURE

Wood experiences a significant loss of strength and stiffness when loaded over period of time. This phenomenon is known as creep-rupture. Several models were developed for the estimation of the reduction of load carrying capacity of timber with time. In this paper, the results of time dependent structural reliability analysis of timber joist produced with Lophiraalata (Ekki) timber specie was presented. Three load duration models were considered in the study, namely: The Model proposed by Wood, Gerhards model, and Nielsen. The timber joist was designed in accordance with the Eurocode 5. The uncertainties in all the basic design variables were fully accommodated in the time dependent reliability analysis. The entire process was implemented using a developed MATLAB program employing First Order Reliability Method (FORM). Time dependent mathematical models for modification of safety index to account for the effect of load duration were proposed. The use of both Gerhards and Nielsen model, for the design of Lophiraalata timber members was recommended.  http://dx.doi.org/10.4314/njt.v36i1.

Methods for the Phenotypic Detection of Extended Spectrum Beta Lactamase (ESBL)-Producing Bacteria

1983. These enzymes possess the ability to inactivate susceptible β-lactam antibiotics i.e. penicillins, first, second and third generation cephalosporins and aztreonam, but not cephamycins and carbapenems . Their mode of action is by hydrolyzing the β-lactam ring. Even before the first β-lactam antibiotic (penicillin) was developed, resistance to β-lactam antibiotics was observed . ESBL genes are plasmids- and transposons- mediated, as such, can be spread easily to other species of bacteria. Resistance of ESBL- producing bacteria to the β-lactam antibiotics is a continuing cause of public health problems , it is increasingly being observed in community and nosocomial acquired infections. Detection and identification of these ESBLs in the laboratory is of prime importance for the selection of appropriate antibiotics to be used in the treatment of infections caused by ESBL- producing bacteria. The aim of this review is to explain in detail , several phenotypic methods used in the detection and confirmation of extended spectrum β lactamases. Keywords: Antibiotic resistance, ESBL, bacteria, phenotypic metho

A Rapid Method of Crude Oil Analysis Using FT-IR Spectroscopy

This study determines the viability of the use of Fourier Transform Infrared (FTIR) spectroscopy as a substitute to traditional petroleum geochemical methods for crude oil characterisation. IR spectra of Crude oil sample containing a mixture of both degraded (sample 151) and non-degraded (sample 145) oils at different concentrations were determined. The IR fingerprints agree with results obtained from GC analysis. Partial least square regression analysis was used to predict saturates for omitted mixtures (10 and 80% 151) and also saturates of five other samples (i.e. 145, 149, 172, H1 and AL10) within acceptable error limits. It therefore, follows, that although some improvements might still need to be made, FTIR spectroscopy can indeed be a viable, simple, cheaper and faster technique of crude oil characterisation compared with the traditional fractionation methods.Keywords: FTIR-ATR spectroscopy; GC-MS; Partial least squares (PLSR). Rapid analysis

Design and optimisation of a spring particle sizer

This thesis describes the results of a series of investigations examining the operational performance followed by the fundamental re-development of two analytical instruments, namely a Pneumatic Spring Particle Sizer (PSPS) and handheld Spring Particle Sizer (handheld SPS) for size distribution analysis of dry powders in the 100 – 2000 μm size range. Each instrument shares the same basic principle of operation involving the use of a closed coil helical extension spring, which is partly filled with the test powder. Particle size distribution data is obtained by stretching the spring to known lengths and measuring the mass of the discharged particles from the spring’s coils. In the case of the Handheld SPS, aimed at on the spot quality control applications, the test particles are discharged from the spring using manual shaking. In the case of the PSPS on the other hand, the particles are discharged using pulsating pressurised air. The design, development and evaluation of two methods for the in-situ measurement of the sample mass within the PSPS are discussed. These include a full-bridge strain gauge assembly and the investigation of the correlation between the minimum fluidisation velocity and the mass of the test sample within the spring. The strain gauge proved to be a successful method producing a mass resolution of ± 1 % for a total sample mass of 280 g. The second method was unsuccessful as it was found that the minimum fluidisation velocity, in most cases did not follow a clear trend with mass. Detailed investigations are conducted aimed at understanding the processes governing the mass discharge rate from the PSPS and hence the sample analysis time by studying the particle migration behaviour. A pulsating fluidised bed of similar dimensions to the spring is used to mimic the behaviour in the spring. Tests involved pulsating fluidisation followed by particle size distribution analysis at equal distances along the length of the bed containing poly-dispersed and mono-dispersed particles. It was observed that any operating or design parameter that promoted the degree of mixing, for example, increasing the fluidising air pulse frequency would reduce the test analysis time. The analysis time also increased with the sample poly-dispersity. In an attempt to reduce the sampling time, the handheld SPS was rotated using a variable speed tumbler as an alternative to manual shaking. Despite the marked reduction in the sampling time, this method resulted in the discharge of particles larger than spring coil openings thereby producing erroneous results. Calibration experiments for the same types of powders revealed a linear relationship between the discharge sample volume and its mass, independent of the particle size in the range 212 – 1000 μm. This allows in-situ measurement of the discharge sample mass in the handheld unit by reading the sample volume collected in the integrated graduated collection cylinder and reference to a previously generated calibration line

Heavy metals concentration and human health risk assessment in groundwater and table water sold in Tudun Murtala Area, Nassarawa Local Government Area, Kano State, Nigeria

This study determines the level of some heavy metals and as well assess human health risk due to chronic intake of metals in water samples obtained from Tudun Murtala area of Nasssarawa local government area, Kano state. Results obtained showed that Pb, Cd, Cr, Fe and Zn concentrations in water samples were within the range of 0.295- 0.579, 0.471- 0.529, 0.550- 1.000, 0.3636 - 0.4545, 0.0814 - 0.173 respectively, while the Chronic daily intake calculated for the metals respectively were also within the range of 0.0086 – 0.0165, 0.0135 – 0.0186, 0.0034 – 0.0262, 0.0023 – 0.0049, 0.0104 – 0.0130. The total hazard quotient for non-cancer risk of Pb and Cd were found highly elevated, being at the range of 21.5 – 41.25 and 27.0 – 37.2 respectively while that of Cr, Zn and Fe where found to be below the standard limit of one. The hazard index of metals also showed a risk in exposure to Pb and Cd and a tolerable range was observed for Cr, Fe and Zn. The incremental lifetime cancer risk of metals developed through oral route showed elevated level in Pb, Cd and Cr, revealing that exposure to the heavy metals in the water samples posed an unacceptable potential cancer risk. While for the other metals, it showed a less or tolerable risk to the inhabitants.Keywords: Heavy metals, hazard quotient, hazard index, incremental lifetime cancer ris

Evaluation of Improved Bioremediation Strategy for the Treatment of Abattoir Wastewater using Bacillus licheniformis ZUL012

The abattoir generates a large volume and variety of biowastes, posing a high risk of environmental contamination, disease outbreaks, and contaminated food. The purpose of this research was to characterize and remediate abattoir wastewater (Aww). The physicochemical characterization of the Aww revealed high level of pollution which served as a baseline for monitoring treatment efficacy. The B. licheniformis ZUL012 isolated from textile wastewater was primed with H2O2 and used to remediate Aww waste water in the current study. This study revealed Aww high pollution level which necessitated a need for the Treatment with this bacterium resulted in a significant decrease in some of the waste water parameters tested. The induced cell reduced the parameters to 155 41 mg/L, 75 mg/L, 454 mg/L, 1750 mg/L, and 1000 mg/L, whereas the naive cell reduced them to 375 mg/L, 776 mg/L, and 3122 mg/L, respectively. This equates to an average reduction of 95 percent (COD), 95 percent (BOD5), 77 percent (TOC), and 71% (TDS) compared to raw wastewater. These novel strategies show that H2O2-induced B. licheniformis ZUL012 could be a viable hybrid-bioremediation option for reducing or transforming the pollutants present in Aww, thereby contributing to compliance with wastewater discharge regulations into bodies of water

Prevalence of malaria among under fives in Tudun-Wada, Jos north local government area of Plateau state, North central Nigeria.

Background: Malaria is a preventable and treatable disease associated with high morbidity and mortality and under fives. It is the third leading cause of death for children under five years world wide. It is a major public health problem in Nigeria. Knowledge of the prevalence in underfives will help in instituting measures to reduce morbidity and mortality associated with it.Methods: A cross sectional study was conducted among 400 under five children in Tudun Wada, Jos North Local Government Area of Plateau State to determine the prevalence of malaria.Results: The age range of the sampled population was between 0 and 60 months with mean of 34 + 8 months. One hundred and sixty four(41%) of the sampled population had malaria. Sixty four(16%) were females while 100(25%) were males,p=0.06.Conclusion: This study demonstrates a high prevalence of malaria among under five children.Key words: prevalence, malaria, underfiv

Determinants of Technical Efficiency of Maize/Cowpea Intercropping Among Women Farmers in Gombe State, Nigeria

The study was conducted to examine the determinants of technical efficiency of maize/cowpea intercropping among women farmers in Gombe State, Nigeria. A multistage sampling technique was adopted in selecting 104 respondents. Data were collected using a well-structured questionnaire supplemented with focus group discussion over a period of four months. Data collected were analyzed using descriptive statistics and stochastic frontier production function model. Results from socio-economic variables revealed that majority (61%) of the respondents were between 40-59 years with an average farm size of 1.88 hectares. The result of stochastic frontier production function analysis showed that all the estimated coefficients (farm size, fertilizer, family labour, quantity of agrochemicals, hired labour and quantity of seed used) of the independent variables in the model were positive and significant at either 1% or 5% level with the exception of quantity of agrochemicals used. The results further revealed that household size, educational level, farming experience, access to extensions services and off farm income generation were the major determinants of technical efficiency in the study area. Findings from this research work also revealed that the mean technical efficiency of the farmers was 0.84 indicating that the women farmers are relatively efficient in maize/cowpea intercropping. The study therefore suggests intensive efforts at expanding the present scope of maize/cowpea intercropping, given the estimated technical efficiency for the production system

TEGDroid: Test Case Generation Approach for Android Apps Considering Context and GUI Events

The advancement in mobile technologies has led to the production of mobile devices (e.g. smartphone) with rich innovative features. This has enabled the development of mobile applications that offer users an advanced and extremely localized context-aware content. The recent dependence of people on mobile applications for various computational needs poses a significant concern on the quality of mobile applications. In order to build a high quality and more reliable applications, there is a need for effective testing techniques to test the applications. Most existing testing technique focuses on GUI events only without sufficient support for context events. This makes it difficult to identify other defects in the changes that can be inclined by context in which an application runs. This paper presents an approach named TEGDroid for generating test case for Android Apps considering both context and GUI Events. The GUI and context events are identified through the static analysis of bytecode, and the analysis of app’s permission from the XML file. An experiment was performed on real world mobile apps to evaluate TEGDroid. Our experimental results show that TEGDroid is effective in identifying context events and had 65%-91% coverage across the eight selected applications. To evaluate the fault detection capability of this approach, mutation testing was performed by introducing mutants to the applications. Results from the mutation analysis shows that 100% of the mutants were killed. This indicates that TEGDroid have the capability to detect faults in mobile apps

DYNAMICS OF GOVERNMENT POLICIES IN NIGERIA’S ECONOMIC DEVELOPMENT (1960-1979)

This paper appraised the dynamics of government policies towards the development of Nigeria’s modern economy. It identified the roles of colonial rule in the creation of Nigerian State and the economic structure that evolved thereof. The paper reviewed the atmosphere of political development and public policies in the Nigerian State between 1960 and 1979 towards building a sustainable and growing economy. It briefly highlighted the economic developments that took place during the period in question, attempting to develop and expand the nation’s economy. The paper discussed the input and output of economic policies from view-lens of political activities. Finally, the paper concluded that weaknesses inherent in the structure of Nigerian State for developmental planning will continue to be affecting the desirable attainment of the country’s economic goals. Keywords: Government policy, Modern Economy, Political development, Economic goals